A Medley of Potpourri

Main isotopes			Decay
	abundance	half-life (t_1/2)	mode	product
⁶³Cu	69.2%	stable
⁶⁴Cu	synth	12.70 h	β⁺	⁶⁴Ni
⁶⁴Cu	synth	12.70 h	β⁻	⁶⁴Zn
⁶⁵Cu	30.9%	stable
⁶⁷Cu	synth	61.83 h	β⁻	⁶⁷Zn

Copper is a chemical element; it has symbol Cu (from Latin cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.

Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from c. 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, c. 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 3500 BC.

In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes cyprium (metal of Cyprus), later corrupted to cuprum (Latin). Coper (Old English) and copper were derived from this, the later spelling first used around 1530.

Commonly encountered compounds are copper(II) salts, which often impart blue or green colors to such minerals as azurite, malachite, and turquoise, and have been used widely and historically as pigments.

Copper used in buildings, usually for roofing, oxidizes to form a green patina of compounds called verdigris. Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents, fungicides, and wood preservatives.

Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found mainly in the liver, muscle, and bone. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.

Characteristics

Physical

A copper disc (99.95% pure) made by continuous casting; etched to reveal crystallites

Copper, silver, and gold are in group 11 of the periodic table; these three metals have one s-orbital electron on top of a filled d-electron shell and are characterized by high ductility, and electrical and thermal conductivity. The filled d-shells in these elements contribute little to interatomic interactions, which are dominated by the s-electrons through metallic bonds. Unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper. At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms.

The softness of copper partly explains its high electrical conductivity (59.6×10⁶ S/m) and high thermal conductivity, second highest (second only to silver) among pure metals at room temperature. This is because the resistivity to electron transport in metals at room temperature originates primarily from scattering of electrons on thermal vibrations of the lattice, which are relatively weak in a soft metal. The maximum possible current density of copper in open air is approximately 3.1×10⁶ A/m², above which it begins to heat excessively.

Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air. This is due to the low plasma frequency of the metal, which lies in the red part of the visible spectrum, causing it to absorb the higher-frequency green and blue colors.

As with other metals, if copper is put in contact with another metal in the presence of an electrolyte, galvanic corrosion will occur.

Chemical

Copper does not react with water, but it does slowly react with atmospheric oxygen to form a layer of brown-black copper oxide which, unlike the rust that forms on iron in moist air, protects the underlying metal from further corrosion (passivation). A green layer of verdigris (copper carbonate) can often be seen on old copper structures, such as the roofing of many older buildings and the Statue of Liberty. Copper tarnishes when exposed to some sulfur compounds, with which it reacts to form various copper sulfides.

Isotopes

There are 29 isotopes of copper. ⁶³
Cu
and ⁶⁵
Cu
are stable, with ⁶³
Cu
comprising approximately 69% of naturally occurring copper; both have a spin of 3⁄2. The other isotopes are radioactive, with the most stable being ⁶⁷
Cu
with a half-life of 61.83 hours. Seven metastable isomers have been characterized; ^68m
Cu
is the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by β⁻, whereas those with a mass number below 64 decay by β⁺. ⁶⁴
Cu
, which has a half-life of 12.7 hours, decays both ways.

⁶²
Cu
and ⁶⁴
Cu
have significant applications. ⁶²
Cu
is used in ⁶²
Cu
Cu-PTSM as a radioactive tracer for positron emission tomography.

Occurrence

Copper is produced in massive stars and is present in the Earth's crust in a proportion of about 50 parts per million (ppm). In nature, copper occurs in a variety of minerals, including native copper, copper sulfides such as chalcopyrite, bornite, digenite, covellite, and chalcocite, copper sulfosalts such as tetrahedite-tennantite, and enargite, copper carbonates such as azurite and malachite, and as copper(I) or copper(II) oxides such as cuprite and tenorite, respectively. The largest mass of elemental copper discovered weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal, with the largest single crystal ever described measuring 4.4 × 3.2 × 3.2 cm. Copper is the 25th most abundant element in Earth's crust, representing 50 ppm compared with 75 ppm for zinc, and 14 ppm for lead.

Typical background concentrations of copper do not exceed 1 ng/m³ in the atmosphere; 150 mg/kg in soil; 30 mg/kg in vegetation; 2 μg/L in freshwater and 0.5 μg/L in seawater.

Production

Chuquicamata, in Chile, is one of the world's largest open pit copper mines.

Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Sites include Chuquicamata, in Chile, Bingham Canyon Mine, in Utah, United States, and El Chino Mine, in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top producer of copper with at least one-third of the world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage. An alternative source of copper for collection currently being researched are polymetallic nodules, which are located at the depths of the Pacific Ocean approximately 3000–6500 meters below sea level. These nodules contain other valuable metals such as cobalt and nickel.

Reserves and prices

Copper has been in use for at least 10,000 years, but more than 95% of all copper ever mined and smelted has been extracted since 1900. As with many natural resources, the total amount of copper on Earth is vast, with around 10¹⁴ tons in the top kilometer of Earth's crust, which is about 5 million years' worth at the current rate of extraction. However, only a tiny fraction of these reserves is economically viable with present-day prices and technologies. Estimates of copper reserves available for mining vary from 25 to 60 years, depending on core assumptions such as the growth rate. Recycling is a major source of copper in the modern world.

The price of copper is volatile. After a peak in 2022 the price unexpectedly fell.

Methods

The great majority of copper ores are sulfides. Common ores are the sulfides chalcopyrite (CuFeS₂), bornite (Cu₅FeS₄) and, to a lesser extent, covellite (CuS) and chalcocite (Cu₂S). These ores occur at the level of <1% Cu. Concentration of the ore is required, which begins with comminution followed by froth flotation. The remaining concentrate is the smelted, which can be described with two simplified equations:

2 Cu₂S + 3 O₂ → 2 Cu₂O + 2 SO₂

Cuprous oxide reacts with cuprous sulfide to convert to blister copper upon heating

2 Cu₂O + Cu₂S → 6 Cu + 2 SO₂

This roasting gives matte copper, roughly 50% Cu by weight, which is purified by electrolysis. Depending on the ore, sometimes other metals are obtained during the electrolysis including platinum and gold.

Aside from sulfides, another family of ores are oxides. Approximately 15% of the world's copper supply derives from these oxides. The beneficiation process for oxides involves extracton with sulfuric acid solutions followed by electrolysis. In parallel with the above method for "concentrated" sulfide and oxide ores, copper is recovered from mine tailings and heaps. A variety of methods are used including leaching with sulfuric acid, ammonia, ferric chloride. Biological methods are also used.

A significant source of copper is from recycling. Recycling is facilitated because copper is usually deployed in its metallic state. In 2001, a typical automobile contained 20–30 kg of copper. Recycling usually begins with some melting process using a blast furnace.

A potential source of copper is polymetallic nodules, which have an estimated concentration 1.3%.

Flowchart of copper refining (Anode casting plant of Uralelektromed)

Blister copper
Smelting
Reverberatory furnace
Slag removal
Copper casting of anodes
Casting wheel
Anodes removal machine
Anodes take-off
Rail cars
Transportation to the tank house

Recycling

Like aluminium, copper is recyclable without any loss of quality, both from raw state and from manufactured products. In volume, copper is the third most recycled metal after iron and aluminium. An estimated 80% of all copper ever mined is still in use today. According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of copper in use in society is 35–55 kg. Much of this is in more-developed countries (140–300 kg per capita) rather than less-developed countries (30–40 kg per capita).

The process of recycling copper is roughly the same as is used to extract copper but requires fewer steps. High-purity scrap copper is melted in a furnace and then reduced and cast into billets and ingots; lower-purity scrap is refined by electroplating in a bath of sulfuric acid.

Environmental impacts

The environmental cost of copper mining was estimated at 3.7 kg CO2eq per kg of copper in 2019. Codelco, a major producer in Chile, reported that in 2020 the company emitted 2.8t CO2eq per ton (2.8 kg CO2eq per kg) of fine copper. Greenhouse gas emissions primarily arise from electricity consumed by the company, especially when sourced from fossil fuels, and from engines required for copper extraction and refinement. Companies that mine land often mismanage waste, rendering the area sterile for life. Additionally, nearby rivers and forests are also negatively impacted. The Philippines is an example of a region where land is overexploited by mining companies.

Copper mining waste in Valea Şesei, Romania, has significantly altered nearby water properties. The water in the affected areas is highly acidic, with a pH range of 2.1–4.9, and shows elevated electrical conductivity levels between 280 and 1561 mS/cm. These changes in water chemistry make the environment inhospitable for fish, essentially rendering the water uninhabitable for aquatic life.

Alloys

Numerous copper alloys have been formulated, many with important uses. Brass is an alloy of copper and zinc. Bronze usually refers to copper-tin alloys, but can refer to any alloy of copper such as aluminium bronze. Copper is one of the most important constituents of silver and karat gold solders used in the jewelry industry, modifying the color, hardness and melting point of the resulting alloys. Some lead-free solders consist of tin alloyed with a small proportion of copper and other metals.

The alloy of copper and nickel, called cupronickel, is used in low-denomination coins, often for the outer cladding. The US five-cent coin (currently called a nickel) consists of 75% copper and 25% nickel in homogeneous composition. Prior to the introduction of cupronickel, which was widely adopted by countries in the latter half of the 20th century, alloys of copper and silver were also used, with the United States using an alloy of 90% silver and 10% copper until 1965, when circulating silver was removed from all coins with the exception of the half dollar—these were debased to an alloy of 40% silver and 60% copper between 1965 and 1970. The alloy of 90% copper and 10% nickel, remarkable for its resistance to corrosion, is used for various objects exposed to seawater, though it is vulnerable to the sulfides sometimes found in polluted harbors and estuaries. Alloys of copper with aluminium (about 7%) have a golden color and are used in decorations. Shakudō is a Japanese decorative alloy of copper containing a low percentage of gold, typically 4–10%, that can be patinated to a dark blue or black color.

Compounds

Copper forms a rich variety of compounds, usually with oxidation states +1 and +2, which are often called cuprous and cupric, respectively. Copper compounds promote or catalyse numerous chemical and biological processes.

Binary compounds

As with other elements, the simplest compounds of copper are binary compounds, i.e. those containing only two elements, the principal examples being oxides, sulfides, and halides. Both cuprous and cupric oxides are known. Among the numerous copper sulfides, important examples include copper(I) sulfide (Cu₂S) and copper monosulfide (CuS).

Cuprous halides with fluorine, chlorine, bromine, and iodine are known, as are cupric halides with fluorine, chlorine, and bromine. Attempts to prepare copper(II) iodide yield only copper(I) iodide and iodine.

2 Cu²⁺ + 4 I⁻ → 2 CuI + I₂

Coordination chemistry

Copper(II) gives a deep blue coloration in the presence of ammonia ligands. The one used here is tetraamminecopper(II) sulfate.

Copper forms coordination complexes with ligands. In aqueous solution, copper(II) exists as [Cu(H
₂O)
₆]²⁺
. This complex exhibits the fastest water exchange rate (speed of water ligands attaching and detaching) for any transition metal aquo complex. Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper(II) hydroxide. A simplified equation is:

Pourbaix diagram for copper in uncomplexed media (anions other than OH- not considered). Ion concentration 0.001 m (mol/kg water). Temperature 25 °C.

Cu²⁺ + 2 OH⁻ → Cu(OH)₂

Aqueous ammonia results in the same precipitate. Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper(II):

Cu(H
₂O)
₄(OH)
₂ + 4 NH₃ → [Cu(H
₂O)
₂(NH
₃)
₄]²⁺
+ 2 H₂O + 2 OH⁻

Many other oxyanions form complexes; these include copper(II) acetate, copper(II) nitrate, and copper(II) carbonate. Copper(II) sulfate forms a blue crystalline pentahydrate, the most familiar copper compound in the laboratory. It is used in a fungicide called the Bordeaux mixture.

Ball-and-stick model of the complex [Cu(NH₃)₄(H₂O)₂]²⁺, illustrating the octahedral coordination geometry common for copper(II)

Polyols, compounds containing more than one alcohol functional group, generally interact with cupric salts. For example, copper salts are used to test for reducing sugars. Specifically, using Benedict's reagent and Fehling's solution the presence of the sugar is signaled by a color change from blue Cu(II) to reddish copper(I) oxide. Schweizer's reagent and related complexes with ethylenediamine and other amines dissolve cellulose. Amino acids such as cystine form very stable chelate complexes with copper(II) including in the form of metal-organic biohybrids (MOBs). Many wet-chemical tests for copper ions exist, one involving potassium ferricyanide, which gives a brilliant blue precipitate with copper(II) salts.

Organocopper chemistry

Compounds that contain a carbon-copper bond are known as organocopper compounds. They are very reactive towards oxygen to form copper(I) oxide and have many uses in chemistry. They are synthesized by treating copper(I) compounds with Grignard reagents, terminal alkynes or organolithium reagents; in particular, the last reaction described produces a Gilman reagent. These can undergo substitution with alkyl halides to form coupling products; as such, they are important in the field of organic synthesis. Copper(I) acetylide is highly shock-sensitive but is an intermediate in reactions such as the Cadiot–Chodkiewicz coupling and the Sonogashira coupling. Conjugate addition to enones and carbocupration of alkynes can also be achieved with organocopper compounds. Copper(I) forms a variety of weak complexes with alkenes and carbon monoxide, especially in the presence of amine ligands.

Copper(III) and copper(IV)

Copper(III) is most often found in oxides. A simple example is potassium cuprate, KCuO₂, a blue-black solid. The most extensively studied copper(III) compounds are the cuprate superconductors. Yttrium barium copper oxide (YBa₂Cu₃O₇) consists of both Cu(II) and Cu(III) centres. Like oxide, fluoride is a highly basic anion and is known to stabilize metal ions in high oxidation states. Both copper(III) and even copper(IV) fluorides are known, K₃CuF₆ and Cs₂CuF₆, respectively.

Some copper proteins form oxo complexes, which, in extensively studied synthetic analog systems, feature copper(III). With tetrapeptides, purple-colored copper(III) complexes are stabilized by the deprotonated amide ligands.

Complexes of copper(III) are also found as intermediates in reactions of organocopper compounds, for example in the Kharasch–Sosnovsky reaction.

History

A timeline of copper illustrates how this metal has advanced human civilization for the past 11,000 years.

Prehistoric

Copper Age

Many tools during the Chalcolithic Era included copper, such as the blade of this replica of Ötzi's axe.

Copper occurs naturally as native metallic copper and was known to some of the oldest civilizations on record. The history of copper use dates to 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. Evidence suggests that gold and meteoric iron (but not smelted iron) were the only metals used by humans before copper. The history of copper metallurgy is thought to follow this sequence: first, cold working of native copper, then annealing, smelting, and, finally, lost-wax casting. In southeastern Anatolia, all four of these techniques appear more or less simultaneously at the beginning of the Neolithic c. 7500 BC.

Copper smelting was independently invented in different places. It was probably discovered in China before 2800 BC, in Central America around 600 AD, and in West Africa about the 9th or 10th century AD. The earliest evidence of lost-wax casting copper comes from an amulet found in Mehrgarh, Pakistan, and is dated to 4000 BC. Investment casting was invented in 4500–4000 BC in Southeast Asia and carbon dating has established mining at Alderley Edge in Cheshire, UK, at 2280 to 1890 BC.

Ötzi the Iceman, a male dated from 3300 to 3200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest an involvement in copper smelting. Experience with copper has assisted the development of other metals; in particular, copper smelting led to the discovery of iron smelting.

Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6500 and 3000 BC. A copper spearpoint found in Wisconsin has been dated to 6500 BC. Copper usage by the indigenous peoples of the Old Copper Complex from the Great Lakes region of North America has been radiometrically dated to as far back as 7500 BC. Indigenous peoples of North America around the Great Lakes may have also been mining copper during this time, making it one of the oldest known examples of copper extraction in the world. There is evidence from prehistoric lead pollution from lakes in Michigan that people in the region began mining copper c. 6000 BC. Evidence suggests that utilitarian copper objects fell increasingly out of use in the Old Copper Complex of North America during the Bronze Age and a shift towards an increased production of ornamental copper objects occurred.

Bronze Age

Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC. Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use. Bronze artifacts from the Vinča culture date to 4500 BC. Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC. Egyptian Blue, or cuprorivaite (calcium copper silicate) is a synthetic pigment that contains copper and started being used in ancient Egypt around 3250 BC. The manufacturing process of Egyptian blue was known to the Romans, but by the fourth century AD the pigment fell out of use and the secret to its manufacturing process became lost. The Romans said the blue pigment was made from copper, silica, lime and natron and was known to them as caeruleum.

The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, and 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), when copper tools were used with stone tools. The term has gradually fallen out of favor because in some parts of the world, the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.

Ancient and post-classical

Chalcolithic copper mine in Timna Valley, Negev Desert, Israel

In Greece, copper was known by the name chalkos (χαλκός). It was an important resource for the Romans, Greeks and other ancient peoples. In Roman times, it was known as aes Cyprium, aes being the generic Latin term for copper alloys and Cyprium from Cyprus, where much copper was mined. The phrase was simplified to cuprum, hence the English copper. Aphrodite (Venus in Rome) represented copper in mythology and alchemy because of its lustrous beauty and its ancient use in producing mirrors; Cyprus, the source of copper, was sacred to the goddess. The seven heavenly bodies known to the ancients were associated with the seven metals known in antiquity, and Venus was assigned to copper, both because of the connection to the goddess and because Venus was the brightest heavenly body after the Sun and Moon and so corresponded to the most lustrous and desirable metal after gold and silver.

Copper was first mined in ancient Britain as early as 2100 BC. Mining at the largest of these mines, the Great Orme, continued into the late Bronze Age. Mining seems to have been largely restricted to supergene ores, which were easier to smelt. The rich copper deposits of Cornwall seem to have been largely untouched, in spite of extensive tin mining in the region, for reasons likely social and political rather than technological.

In North America, native copper is known to have been extracted from sites on Isle Royale with primitive stone tools between 800 and 1600 AD. Copper annealing was being performed in the North American city of Cahokia around 1000–1300 AD. There are several exquisite copper plates, known as the Mississippian copper plates that have been found in North America in the area around Cahokia dating from this time period (1000–1300 AD). The copper plates were thought to have been manufactured at Cahokia before ending up elsewhere in the Midwest and southeastern United States like the Wulfing cache and Etowah plates.

In South America a copper mask dated to 1000 BC found in the Argentinian Andes is the oldest known copper artifact discovered in the Andes. Peru has been considered the origin for early copper metallurgy in pre-Columbian America, but the copper mask from Argentina suggests that the Cajón del Maipo of the southern Andes was another important center for early copper workings in South America. Copper metallurgy was flourishing in South America, particularly in Peru around 1000 AD. Copper burial ornamentals from the 15th century have been uncovered, but the metal's commercial production did not start until the early 20th century.

The cultural role of copper has been important, particularly in currency. Romans in the 6th through 3rd centuries BC used copper lumps as money. At first, the copper itself was valued, but gradually the shape and look of the copper became more important. Julius Caesar had his own coins made from brass, while Octavianus Augustus Caesar's coins were made from Cu-Pb-Sn alloys. With an estimated annual output of around 15,000 t, Roman copper mining and smelting activities reached a scale unsurpassed until the time of the Industrial Revolution; the provinces most intensely mined were those of Hispania, Cyprus and in Central Europe.

The gates of the Temple of Jerusalem used Corinthian bronze treated with depletion gilding. The process was most prevalent in Alexandria, where alchemy is thought to have begun. In ancient India, copper was used in the holistic medical science Ayurveda for surgical instruments and other medical equipment. Ancient Egyptians (~2400 BC) used copper for sterilizing wounds and drinking water, and later to treat headaches, burns, and itching.

Modern

Acid mine drainage affecting the stream running from the disused Parys Mountain copper mines

The Great Copper Mountain was a mine in Falun, Sweden, that operated from the 10th century to 1992. It satisfied two-thirds of Europe's copper consumption in the 17th century and helped fund many of Sweden's wars during that time. It was referred to as the nation's treasury; Sweden had a copper backed currency.

Copper is used in roofing, currency, and for photographic technology known as the daguerreotype. Copper was used in Renaissance sculpture, and was used to construct the Statue of Liberty; copper continues to be used in construction of various types. Copper plating and copper sheathing were widely used to protect the under-water hulls of ships, a technique pioneered by the British Admiralty in the 18th century. The Norddeutsche Affinerie in Hamburg was the first modern electroplating plant, starting its production in 1876. The German scientist Gottfried Osann invented powder metallurgy in 1830 while determining the metal's atomic mass; around then it was discovered that the amount and type of alloying element (e.g., tin) to copper would affect bell tones.

During the rise in demand for copper for the Age of Electricity, from the 1880s until the Great Depression of the 1930s, the United States produced one third to half the world's newly mined copper. Major districts included the Keweenaw district of northern Michigan, primarily native copper deposits, which was eclipsed by the vast sulphide deposits of Butte, Montana, in the late 1880s, which itself was eclipsed by porphyry deposits of the Southwest United States, especially at Bingham Canyon, Utah, and Morenci, Arizona. Introduction of open pit steam shovel mining and innovations in smelting, refining, flotation concentration and other processing steps led to mass production. Early in the twentieth century, Arizona ranked first, followed by Montana, then Utah and Michigan.

Flash smelting was developed by Outokumpu in Finland and first applied at Harjavalta in 1949; the energy-efficient process accounts for 50% of the world's primary copper production.

The Intergovernmental Council of Copper Exporting Countries, formed in 1967 by Chile, Peru, Zaire and Zambia, operated in the copper market as OPEC does in oil, though it never achieved the same influence, particularly because the second-largest producer, the United States, was never a member; it was dissolved in 1988.

Applications

The major applications of copper are electrical wire (60%), roofing and plumbing (20%), and industrial machinery (15%). Copper is used mostly as a pure metal, but when greater hardness is required, it is put into such alloys as brass and bronze (5% of total use). For more than two centuries, copper paint has been used on boat hulls to control the growth of plants and shellfish. A small part of the copper supply is used for nutritional supplements and fungicides in agriculture. Machining of copper is possible, although alloys are preferred for good machinability in creating intricate parts.

Wire and cable

Despite competition from other materials, copper remains the preferred electrical conductor in nearly all categories of electrical wiring except overhead electric power transmission where aluminium is often preferred. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Electrical wiring is the most important market for the copper industry. This includes structural power wiring, power distribution cable, appliance wire, communications cable, automotive wire and cable, and magnet wire. Roughly half of all copper mined is used for electrical wire and cable conductors. Many electrical devices rely on copper wiring because of its multitude of inherent beneficial properties, such as its high electrical conductivity, tensile strength, ductility, creep (deformation) resistance, corrosion resistance, low thermal expansion, high thermal conductivity, ease of soldering, malleability, and ease of installation.

For a short period from the late 1960s to the late 1970s, copper wiring was replaced by aluminium wiring in many housing construction projects in America. The new wiring was implicated in a number of house fires and the industry returned to copper.

Electronics and related devices

Copper electrical busbars distributing power to a large building

Integrated circuits and printed circuit boards increasingly feature copper in place of aluminium because of its superior electrical conductivity; heat sinks and heat exchangers use copper because of its superior heat dissipation properties. Electromagnets, vacuum tubes, cathode ray tubes, and magnetrons in microwave ovens use copper, as do waveguides for microwave radiation.

Electric motors

Copper's superior conductivity enhances the efficiency of electrical motors. This is important because motors and motor-driven systems account for 43–46% of all global electricity consumption and 69% of all electricity used by industry. Increasing the mass and cross section of copper in a coil increases the efficiency of the motor. Copper motor rotors, a new technology designed for motor applications where energy savings are prime design objectives, are enabling general-purpose induction motors to meet and exceed National Electrical Manufacturers Association (NEMA) premium efficiency standards.

Renewable energy production

Renewable energy sources such as solar, wind, tidal, hydro, biomass, and geothermal have become significant sectors of the energy market. The rapid growth of these sources in the 21st century has been prompted by increasing costs of fossil fuels as well as their environmental impact issues that significantly lowered their use.

Copper plays an important role in these renewable energy systems. Copper usage averages up to five times more in renewable energy systems than in traditional power generation, such as fossil fuel and nuclear power plants. Since copper is an excellent thermal and electrical conductor among engineering metals (second only to silver), electrical systems that utilize copper generate and transmit energy with high efficiency and with minimum environmental impacts.

When choosing electrical conductors, facility planners and engineers factor capital investment costs of materials against operational savings due to their electrical energy efficiencies over their useful lives, plus maintenance costs. Copper often fares well in these calculations. A factor called "copper usage intensity,” is a measure of the quantity of copper necessary to install one megawatt of new power-generating capacity.

When planning for a new renewable power facility, engineers and product specifiers seek to avoid supply shortages of selected materials. According to the United States Geological Survey, in-ground copper reserves have increased more than 700% since 1950, from almost 100 million tonnes to 720 million tonnes in 2017, despite the fact that world refined usage has more than tripled in the last 50 years. Copper resources are estimated to exceed 5,000 million tonnes.

Bolstering the supply from copper extraction is the more than 30 percent of copper installed from 2007 to 2017 that came from recycled sources. Its recycling rate is higher than any other metal.

Architecture

Copper has been used since ancient times as a durable, corrosion resistant, and weatherproof architectural material. Roofs, flashings, rain gutters, downspouts, domes, spires, vaults, and doors have been made from copper for hundreds or thousands of years. Copper's architectural use has been expanded in modern times to include interior and exterior wall cladding, building expansion joints, radio frequency shielding, and antimicrobial and decorative indoor products such as attractive handrails, bathroom fixtures, and counter tops. Some of copper's other important benefits as an architectural material include low thermal movement, light weight, lightning protection, and recyclability.

The metal's distinctive natural green patina has long been coveted by architects and designers. The final patina is a particularly durable layer that is highly resistant to atmospheric corrosion, thereby protecting the underlying metal against further weathering. It can be a mixture of carbonate and sulfate compounds in various amounts, depending upon environmental conditions such as sulfur-containing acid rain.Architectural copper and its alloys can also be 'finished' to take on a particular look, feel, or color. Finishes include mechanical surface treatments, chemical coloring, and coatings.

Copper has excellent brazing and soldering properties and can be welded; the best results are obtained with gas metal arc welding.

Antibiofouling

Copper is biostatic, meaning bacteria and many other forms of life will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal and copper-based paint. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions and have strong structural and corrosion-resistant properties in marine environments.

Antimicrobial

Copper-alloy touch surfaces have natural properties that destroy a wide range of microorganisms (e.g., E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Clostridium difficile, influenza A virus, adenovirus, SARS-CoV-2, and fungi). Indians have been using copper vessels since ancient times for storing water, even before modern science realized its antimicrobial properties. Some copper alloys were proven to kill more than 99.9% of disease-causing bacteria within just two hours when cleaned regularly. The United States Environmental Protection Agency (EPA) has approved the registrations of these copper alloys as "antimicrobial materials with public health benefits"; that approval allows manufacturers to make legal claims to the public health benefits of products made of registered alloys. In addition, the EPA has approved a long list of antimicrobial copper products made from these alloys, such as bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, and shopping cart handles. Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in plumbing systems. Antimicrobial copper alloy products are now being installed in healthcare facilities in the U.K., Ireland, Japan, Korea, France, Denmark, and Brazil, as well as being called for in the US, and in the subway transit system in Santiago, Chile, where copper–zinc alloy handrails were installed in some 30 stations between 2011 and 2014. Textile fibers can be blended with copper to create antimicrobial protective fabrics.

Copper demand

Total world production in 2023 is expected to be almost 23 million metric tons. Copper demand is increasing due to the ongoing energy transition to electricity. China accounts for over half the demand.

For some purposes, other metals can substitute, aluminium wire was substituted in many applications, but improper design resulted in fire hazards. The safety issues have since been solved by use of larger sizes of aluminium wire (#8AWG and up), and properly designed aluminium wiring is still being installed in place of copper. For example, the Airbus A380 uses aluminum wire in place of copper wire for electrical power transmission.

Speculative investing

Copper may be used as a speculative investment due to the predicted increase in use from worldwide infrastructure growth, and the important role it has in producing wind turbines, solar panels, and other renewable energy sources. Another reason predicted demand increases is the fact that electric cars contain an average of 3.6 times as much copper as conventional cars, although the effect of electric cars on copper demand is debated. Some people invest in copper through copper mining stocks, ETFs, and futures. Others store physical copper in the form of copper bars or rounds although these tend to carry a higher premium in comparison to precious metals. Those who want to avoid the premiums of copper bullion alternatively store old copper wire, copper tubing or American pennies made before 1982.

Folk medicine

Copper is commonly used in jewelry, and according to some folklore, copper bracelets relieve arthritis symptoms. In one trial for osteoarthritis and one trial for rheumatoid arthritis, no differences were found between copper bracelet and control (non-copper) bracelet.No evidence shows that copper can be absorbed through the skin. If it were, it might lead to copper poisoning.

Degradation

Chromobacterium violaceum and Pseudomonas fluorescens can both mobilize solid copper as a cyanide compound. The ericoid mycorrhizal fungi associated with Calluna, Erica and Vaccinium can grow in metalliferous soils containing copper. The ectomycorrhizal fungus Suillus luteus protects young pine trees from copper toxicity. A sample of the fungus Aspergillus niger was found growing from gold mining solution and was found to contain cyano complexes of such metals as gold, silver, copper, iron, and zinc. The fungus also plays a role in the solubilization of heavy metal sulfides.

Biological role

Biochemistry

Copper proteins have diverse roles in biological electron transport and oxygen transportation, processes that exploit the easy interconversion of Cu(I) and Cu(II). Copper is essential in the aerobic respiration of all eukaryotes. In mitochondria, it is found in cytochrome c oxidase, which is the last protein in oxidative phosphorylation. Cytochrome c oxidase is the protein that binds the O₂ between a copper and an iron; the protein transfers 8 electrons to the O₂ molecule to reduce it to two molecules of water. Copper is also found in many superoxide dismutases, proteins that catalyze the decomposition of superoxides by converting it (by disproportionation) to oxygen and hydrogen peroxide:

Cu²⁺-SOD + O₂⁻ → Cu⁺-SOD + O₂ (reduction of copper; oxidation of superoxide)
Cu⁺-SOD + O₂⁻ + 2H⁺ → Cu²⁺-SOD + H₂O₂ (oxidation of copper; reduction of superoxide)

The protein hemocyanin is the oxygen carrier in most mollusks and some arthropods such as the horseshoe crab (Limulus polyphemus). Because hemocyanin is blue, these organisms have blue blood rather than the red blood of iron-based hemoglobin. Structurally related to hemocyanin are the laccases and tyrosinases. Instead of reversibly binding oxygen, these proteins hydroxylate substrates, illustrated by their role in the formation of lacquers. The biological role for copper commenced with the appearance of oxygen in Earth's atmosphere. Several copper proteins, such as the "blue copper proteins", do not interact directly with substrates; hence they are not enzymes. These proteins relay electrons by the process called electron transfer.

A unique tetranuclear copper center has been found in nitrous-oxide reductase.

Chemical compounds which were developed for treatment of Wilson's disease have been investigated for use in cancer therapy.

Nutrition

Copper is an essential trace element in plants and animals, but not all microorganisms. The human body contains copper at a level of about 1.4 to 2.1 mg per kg of body mass.

Absorption

Copper is absorbed in the gut, then transported to the liver bound to albumin. After processing in the liver, copper is distributed to other tissues in a second phase, which involves the protein ceruloplasmin, carrying the majority of copper in blood. Ceruloplasmin also carries the copper that is excreted in milk, and is particularly well-absorbed as a copper source. Copper in the body normally undergoes enterohepatic circulation (about 5 mg a day, vs. about 1 mg per day absorbed in the diet and excreted from the body), and the body is able to excrete some excess copper, if needed, via bile, which carries some copper out of the liver that is not then reabsorbed by the intestine.

Dietary recommendations

The U.S. Institute of Medicine (IOM) updated the estimated average requirements (EARs) and recommended dietary allowances (RDAs) for copper in 2001. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake (AI) is used instead. The AIs for copper are: 200 μg of copper for 0–6-month-old males and females, and 220 μg of copper for 7–12-month-old males and females. For both sexes, the RDAs for copper are: 340 μg of copper for 1–3 years old, 440 μg of copper for 4–8 years old, 700 μg of copper for 9–13 years old, 890 μg of copper for 14–18 years old and 900 μg of copper for ages 19 years and older. For pregnancy, 1,000 μg. For lactation, 1,300 μg. As for safety, the IOM also sets tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of copper the UL is set at 10 mg/day. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes.

The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States. For women and men ages 18 and older the AIs are set at 1.3 and 1.6 mg/day, respectively. AIs for pregnancy and lactation is 1.5 mg/day. For children ages 1–17 years the AIs increase with age from 0.7 to 1.3 mg/day. These AIs are higher than the U.S. RDAs. The European Food Safety Authority reviewed the same safety question and set its UL at 5 mg/day, which is half the U.S. value.

For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For copper labeling purposes 100% of the Daily Value was 2.0 mg, but as of May 27, 2016, it was revised to 0.9 mg to bring it into agreement with the RDA. A table of the old and new adult daily values is provided at Reference Daily Intake.

Deficiency

Because of its role in facilitating iron uptake, copper deficiency can produce anemia-like symptoms, neutropenia, bone abnormalities, hypopigmentation, impaired growth, increased incidence of infections, osteoporosis, hyperthyroidism, and abnormalities in glucose and cholesterol metabolism. Conversely, Wilson's disease causes an accumulation of copper in body tissues.

Severe deficiency can be found by testing for low plasma or serum copper levels, low ceruloplasmin, and low red blood cell superoxide dismutase levels; these are not sensitive to marginal copper status. The "cytochrome c oxidase activity of leucocytes and platelets" has been stated as another factor in deficiency, but the results have not been confirmed by replication.

Toxicity

Gram quantities of various copper salts have been taken in suicide attempts and produced acute copper toxicity in humans, possibly due to redox cycling and the generation of reactive oxygen species that damage DNA. Corresponding amounts of copper salts (30 mg/kg) are toxic in animals. A minimum dietary value for healthy growth in rabbits has been reported to be at least 3 ppm in the diet. However, higher concentrations of copper (100 ppm, 200 ppm, or 500 ppm) in the diet of rabbits may favorably influence feed conversion efficiency, growth rates, and carcass dressing percentages.

Chronic copper toxicity does not normally occur in humans because of transport systems that regulate absorption and excretion. Autosomal recessive mutations in copper transport proteins can disable these systems, leading to Wilson's disease with copper accumulation and cirrhosis of the liver in persons who have inherited two defective genes.

Elevated copper levels have also been linked to worsening symptoms of Alzheimer's disease.

Human exposure

In the US, the Occupational Safety and Health Administration (OSHA) has designated a permissible exposure limit (PEL) for copper dust and fumes in the workplace as a time-weighted average (TWA) of 1 mg/m³. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 1 mg/m³, time-weighted average. The IDLH (immediately dangerous to life and health) value is 100 mg/m³.

Copper is a constituent of tobacco smoke. The tobacco plant readily absorbs and accumulates heavy metals, such as copper from the surrounding soil into its leaves. These are readily absorbed into the user's body following smoke inhalation. The health implications are not clear.

Neuropharmacology

From Wikipedia, the free encyclopedia

Neuropharmacology is the study of how drugs affect function in the nervous system, and the neural mechanisms through which they influence behavior. There are two main branches of neuropharmacology: behavioral and molecular. Behavioral neuropharmacology focuses on the study of how drugs affect human behavior (neuropsychopharmacology), including the study of how drug dependence and addiction affect the human brain. Molecular neuropharmacology involves the study of neurons and their neurochemical interactions, with the overall goal of developing drugs that have beneficial effects on neurological function. Both of these fields are closely connected, since both are concerned with the interactions of neurotransmitters, neuropeptides, neurohormones, neuromodulators, enzymes, second messengers, co-transporters, ion channels, and receptor proteins in the central and peripheral nervous systems. Studying these interactions, researchers are developing drugs to treat many different neurological disorders, including pain, neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, psychological disorders, addiction, and many others.

History

Neuropharmacology did not appear in the scientific field until, in the early part of the 20th century, scientists were able to figure out a basic understanding of the nervous system and how nerves communicate between one another. Before this discovery, there were drugs that had been found that demonstrated some type of influence on the nervous system. In the 1930s, French scientists began working with a compound called phenothiazine in the hope of synthesizing a drug that would be able to combat malaria. Though this drug showed very little hope in the use against malaria-infected individuals, it was found to have sedative effects along with what appeared to be beneficial effects toward patients with Parkinson's disease. This black box method, wherein an investigator would administer a drug and examine the response without knowing how to relate drug action to patient response, was the main approach to this field, until, in the late 1940s and early 1950s, scientists were able to identify specific neurotransmitters, such as norepinephrine (involved in the constriction of blood vessels and the increase in heart rate and blood pressure), dopamine (the chemical whose shortage is involved in Parkinson's disease), and serotonin (soon to be recognized as deeply connected to depression). In the 1950s, scientists also became better able to measure levels of specific neurochemicals in the body and thus correlate these levels with behavior. The invention of the voltage clamp in 1949 allowed for the study of ion channels and the nerve action potential. These two major historical events in neuropharmacology allowed scientists not only to study how information is transferred from one neuron to another but also to study how a neuron processes this information within itself.

Overview

Neuropharmacology is a very broad region of science that encompasses many aspects of the nervous system from single neuron manipulation to entire areas of the brain, spinal cord, and peripheral nerves. To better understand the basis behind drug development, one must first understand how neurons communicate with one another.

Neurochemical interactions

To understand the potential advances in medicine that neuropharmacology can bring, it is important to understand how human behavior and thought processes are transferred from neuron to neuron and how medications can alter the chemical foundations of these processes.

Neurons are known as excitable cells because on its surface membrane there are an abundance of proteins known as ion-channels that allow small charged particles to pass in and out of the cell. The structure of the neuron allows chemical information to be received by its dendrites, propagated through the perikaryon (cell body) and down its axon, and eventually passing on to other neurons through its axon terminal. These voltage-gated ion channels allow for rapid depolarization throughout the cell. This depolarization, if it reaches a certain threshold, will cause an action potential. Once the action potential reaches the axon terminal, it will cause an influx of calcium ions into the cell. The calcium ions will then cause vesicles, small packets filled with neurotransmitters, to bind to the cell membrane and release its contents into the synapse. This cell is known as the pre-synaptic neuron, and the cell that interacts with the neurotransmitters released is known as the post-synaptic neuron. Once the neurotransmitter is released into the synapse, it can either bind to receptors on the post-synaptic cell, the pre-synaptic cell can re-uptake it and save it for later transmission, or it can be broken down by enzymes in the synapse specific to that certain neurotransmitter. These three different actions are major areas where drug action can affect communication between neurons.

There are two types of receptors that neurotransmitters interact with on a post-synaptic neuron. The first types of receptors are ligand-gated ion channels or LGICs. LGIC receptors are the fastest types of transduction from chemical signal to electrical signal. Once the neurotransmitter binds to the receptor, it will cause a conformational change that will allow ions to directly flow into the cell. The second types are known as G-protein-coupled receptors or GPCRs. These are much slower than LGICs due to an increase in the amount of biochemical reactions that must take place intracellularly. Once the neurotransmitter binds to the GPCR protein, it causes a cascade of intracellular interactions that can lead to many different types of changes in cellular biochemistry, physiology, and gene expression. Neurotransmitter/receptor interactions in the field of neuropharmacology are extremely important because many drugs that are developed today have to do with disrupting this binding process.

Molecular neuropharmacology

Molecular neuropharmacology involves the study of neurons and their neurochemical interactions, and receptors on neurons, with the goal of developing new drugs that will treat neurological disorders such as pain, neurodegenerative diseases, and psychological disorders (also known in this case as neuropsychopharmacology). There are a few technical words that must be defined when relating neurotransmission to receptor action:

Agonist – a molecule that binds to a receptor protein and activates that receptor
Competitive antagonist – a molecule that binds to the same site on the receptor protein as the agonist, preventing activation of the receptor
Non-competitive antagonist – a molecule that binds to a receptor protein on a different site than that of the agonist, but causes a conformational change in the protein that does not allow activation.

The following neurotransmitter/receptor interactions can be affected by synthetic compounds that act as one of the three above. Sodium/potassium ion channels can also be manipulated throughout a neuron to induce inhibitory effects of action potentials.

GABA

The GABA neurotransmitter mediates the fast synaptic inhibition in the central nervous system. When GABA is released from its pre-synaptic cell, it will bind to a receptor (most likely the GABA_A receptor) that causes the post-synaptic cell to hyperpolarize (stay below its action potential threshold). This will counteract the effect of any excitatory manipulation from other neurotransmitter/receptor interactions.

This GABA_A receptor contains many binding sites that allow conformational changes and are the primary target for drug development. The most common of these binding sites, benzodiazepine, allows for both agonist and antagonist effects on the receptor. A common drug, diazepam, acts as an allosteric enhancer at this binding site. Another receptor for GABA, known as GABA_B, can be enhanced by a molecule called baclofen. This molecule acts as an agonist, therefore activating the receptor, and is known to help control and decrease spastic movement.

Dopamine

The dopamine neurotransmitter mediates synaptic transmission by binding to five specific GPCRs. These five receptor proteins are separated into two classes due to whether the response elicits an excitatory or inhibitory response on the post-synaptic cell. There are many types of drugs, legal and illegal, that affect dopamine and its interactions in the brain. With Parkinson's disease, a disease that decreases the amount of dopamine in the brain, the dopamine precursor Levodopa is given to the patient due to the fact that dopamine cannot cross the blood–brain barrier and L-dopa can. Some dopamine agonists are also given to Parkinson's patients that have a disorder known as restless leg syndrome or RLS. Some examples of these are ropinirole and pramipexole.

Psychological disorders like that of attention deficit hyperactivity disorder (ADHD) can be treated with drugs like methylphenidate (also known as Ritalin), which block the re-uptake of dopamine by the pre-synaptic cell, thereby providing an increase of dopamine left in the synaptic gap. This increase in synaptic dopamine will increase binding to receptors of the post-synaptic cell. This same mechanism is also used by other illegal and more potent stimulant drugs such as cocaine.

Serotonin

The neurotransmitter serotonin has the ability to mediate synaptic transmission through either GPCR's or LGIC receptors. The excitatory or inhibitory post-synaptic effects of serotonin are determined by the type of receptor expressed in a given brain region. The most popular and widely used drugs for the regulation of serotonin during depression are known as SSRIs or selective serotonin reuptake inhibitors. These drugs inhibit the transport of serotonin back into the pre-synaptic neuron, leaving more serotonin in the synaptic gap.

Before the discovery of SSRIs, there were also drugs that inhibited the enzyme that breaks down serotonin. MAOIs or monoamine oxidase inhibitors increased the amount of serotonin in the synapse, but had many side-effects including intense migraines and high blood pressure. This was eventually linked to the drugs interacting with a common chemical known as tyramine found in many types of food.

Ion channels

Ion channels located on the surface membrane of the neuron allows for an influx of sodium ions and outward movement of potassium ions during an action potential. Selectively blocking these ion channels will decrease the likelihood of an action potential to occur. The drug riluzole is a neuroprotective drug that blocks sodium ion channels. Since these channels cannot activate, there is no action potential, and the neuron does not perform any transduction of chemical signals into electrical signals and the signal does not move on. This drug is used as an anesthetic as well as a sedative.

Behavioral neuropharmacology

One form of behavioral neuropharmacology focuses on the study of drug dependence and how drug addiction affects the human mind. Most research has shown that the major part of the brain that reinforces addiction through neurochemical reward is the nucleus accumbens. The image to the right shows how dopamine is projected into this area. Long-term excessive alcohol use can cause dependence and addiction. How this addiction occurs is described below.

Ethanol

Alcohol's rewarding and reinforcing (i.e., addictive) properties are mediated through its effects on dopamine neurons in the mesolimbic reward pathway, which connects the ventral tegmental area to the nucleus accumbens (NAcc). One of alcohol's primary effects is the allosteric inhibition of NMDA receptors and facilitation of GABA_A receptors (e.g., enhanced GABA_A receptor-mediated chloride flux through allosteric regulation of the receptor). At high doses, ethanol inhibits most ligand gated ion channels and voltage gated ion channels in neurons as well. Alcohol inhibits sodium-potassium pumps in the cerebellum and this is likely how it impairs cerebellar computation and body co-ordination.

With acute alcohol consumption, dopamine is released in the synapses of the mesolimbic pathway, in turn heightening activation of postsynaptic D1 receptors. The activation of these receptors triggers postsynaptic internal signaling events through protein kinase A which ultimately phosphorylate cAMP response element binding protein (CREB), inducing CREB-mediated changes in gene expression.

With chronic alcohol intake, consumption of ethanol similarly induces CREB phosphorylation through the D1 receptor pathway, but it also alters NMDA receptor function through phosphorylation mechanisms; an adaptive downregulation of the D1 receptor pathway and CREB function occurs as well. Chronic consumption is also associated with an effect on CREB phosphorylation and function via postsynaptic NMDA receptor signaling cascades through a MAPK/ERK pathway and CAMK-mediated pathway. These modifications to CREB function in the mesolimbic pathway induce expression (i.e., increase gene expression) of ΔFosB in the NAcc, where ΔFosB is the "master control protein" that, when overexpressed in the NAcc, is necessary and sufficient for the development and maintenance of an addictive state (i.e., its overexpression in the nucleus accumbens produces and then directly modulates compulsive alcohol consumption).

Research

Parkinson's disease

Parkinson's disease is a neurodegenerative disease described by the selective loss of dopaminergic neurons located in the substantia nigra. Today, the most commonly used drug to combat this disease is levodopa or L-DOPA. This precursor to dopamine can penetrate through the blood–brain barrier, whereas the neurotransmitter dopamine cannot. There has been extensive research to determine whether L-dopa is a better treatment for Parkinson's disease rather than other dopamine agonists. Some believe that the long-term use of L-dopa will compromise neuroprotection and, thus, eventually lead to dopaminergic cell death. Though there has been no proof, in-vivo or in-vitro, some still believe that the long-term use of dopamine agonists is better for the patient.

Alzheimer's disease

While there are a variety of hypotheses that have been proposed for the cause of Alzheimer's disease, the knowledge of this disease is far from complete to explain, making it difficult to develop methods for treatment. In the brain of Alzheimer's patients, both neuronal nicotinic acetylcholine (nACh) receptors and NMDA receptors are known to be down-regulated. Thus, four anticholinesterases have been developed and approved by the U.S. Food and Drug Administration (FDA) for the treatment in the U.S.A. However, these are not ideal drugs, considering their side-effects and limited effectiveness. One promising drug, nefiracetam, is being developed for the treatment of Alzheimer's and other patients with dementia, and has unique actions in potentiating the activity of both nACh receptors and NMDA receptors.

Future

With advances in technology and our understanding of the nervous system, the development of drugs will continue with increasing drug sensitivity and specificity. Structure–activity relationships are a major area of research within neuropharmacology; an attempt to modify the effect or the potency (i.e., activity) of bioactive chemical compounds by modifying their chemical structures.

Self-esteem

From Wikipedia, the free encyclopedia

The construct of self-esteem has been shown to be a desirable one in psychology, as it is associated with a variety of positive outcomes, such as academic achievement, relationship satisfaction, happiness, and lower rates of criminal behavior. The benefits of high self-esteem are thought to include improved mental and physical health, and less anti-social behavior while drawbacks of low self-esteem have been found to be anxiety, loneliness, and increased vulnerability to substance abuse.

Self-esteem can apply to a specific attribute or globally. Psychologists usually regard self-esteem as an enduring personality characteristic (trait self-esteem), though normal, short-term variations (state self-esteem) also exist. Synonyms or near-synonyms of self-esteem include: self-worth, self-regard, self-respect, and self-integrity.

History

The concept of self-esteem has its origins in the 18th century, first expressed in the writings of the Scottish enlightenment thinker David Hume. Hume posits that it is important to value and think well of oneself because it serves a motivational function that enables people to explore their full potential. The identification of self-esteem as a distinct psychological construct has its origins in the work of philosopher and psychologist, William James. James identified multiple dimensions of the self, with two levels of hierarchy: processes of knowing (called the "I-self") and the resulting knowledge about the self (the "Me-self"). The observation about the self and storage of those observations by the I-self creates three types of knowledge, which collectively account for the Me-self, according to James. These are the material self, social self, and spiritual self. The social self comes closest to self-esteem, comprising all characteristics recognized by others. The material self consists of representations of the body and possessions and the spiritual self of descriptive representations and evaluative dispositions regarding the self. This view of self-esteem as the collection of an individual's attitudes toward itself remains today.

In the mid-1960s, social psychologist Morris Rosenberg defined self-esteem as a feeling of self-worth and developed the Rosenberg self-esteem scale (RSES), which became the most widely used scale to measure self-esteem in the social sciences.

In the early 20th century, the behaviorist movement shunned introspective study of mental processes, emotions, and feelings, replacing introspection with objective study through experiments on behaviors observed in relation with the environment. Behaviorism viewed the human being as an animal subject to reinforcements, and suggested making psychology an experimental science, similar to chemistry or biology. Consequently, clinical trials on self-esteem were overlooked, since behaviorists considered the idea less amenable to rigorous measurement.

In the mid-20th century, the rise of phenomenology and humanistic psychology led to a renewed interest in self-esteem as a treatment for psychological disorders such as depression, anxiety, and personality disorders. Psychologists started to consider the relationship between psychotherapy and the personal satisfaction of people with high self-esteem as useful to the field. This led to new elements being introduced to the concept of self-esteem, including the reasons why people tend to feel less worthy and why people become discouraged or unable to meet challenges by themselves.

In 1992, the political scientist Francis Fukuyama associated self-esteem with what Plato called thymos—the "spiritedness" part of the Platonic soul.

From 1997, the core self-evaluations approach included self-esteem as one of four dimensions that comprise one's fundamental appraisal of oneself—along with locus of control, neuroticism, and self-efficacy. The concept of core self-evaluations has since proven to have the ability to predict job satisfaction and job performance. Self-esteem may be essential to self-evaluation.

In public policy

The importance of self-esteem gained endorsement from some government and non-government groups starting around the 1970s, such that one can speak of a self-esteem movement. This movement provides evidence that psychological research can shape public policy. This has expanded to recent years such as 2023 where psychologists are planning to re-invent the approach to research, treatments, and therapy. The new approach emphasizes population health where psychological researchers have prioritized one-one therapy in regards to analyzing social emotional conflict like low self-esteem. The underlying idea of the movement was that low self-esteem was the root of problems for individuals, making it the root of societal problems and dysfunctions. A leading figure of the movement, psychologist Nathaniel Branden, stated: "[I] cannot think of a single psychological problem – from anxiety and depression, to fear of intimacy or of success, to spouse battery or child molestation – that is not traced back to the problem of low self-esteem".

It was once thought that self-esteem was primarily a feature of Western individualistic societies, as it was not observed in collectivist cultures such as Japan. Concern about low self-esteem and its many presumed negative consequences led California assemblyman, John Vasconcellos to work to set up and fund the Task Force on Self-Esteem and Personal and Social Responsibility, in California, in 1986. Vasconcellos argued that this task force could combat many of the state's problems – from crime and teen pregnancy to school underachievement and pollution. He compared increasing self-esteem to giving out a vaccine for a disease: it could help protect people from being overwhelmed by life's challenges.

The task force set up committees in many California counties and formed a committee of scholars to review the available literature on self-esteem. This committee found very small associations between low self-esteem and its assumed consequences, ultimately showing that low self-esteem was not the root of all societal problems and not as important as the committee had originally thought. However, the authors of the paper that summarized the review of the literature still believed that self-esteem is an independent variable that affects major social problems. The task force disbanded in 1995, and the National Council for Self-Esteem and later the National Association for Self-Esteem (NASE) was established, taking on the task force's mission. Vasconcellos and Jack Canfield were members of its advisory board in 2003, and members of its masters' coalition included Anthony Robbins, Bernie Siegel, and Gloria Steinem.

Theories

Many early theories suggested that self-esteem is a basic human need or motivation. American psychologist, Abraham Maslow included self-esteem in his hierarchy of human needs. He described two different forms of "esteem": the need for respect from others in the form of recognition, success, and admiration, and the need for self-respect in the form of self-love, self-confidence, skill, or aptitude. Respect from others was believed to be more fragile and easily lost than inner self-esteem. According to Maslow, without the fulfillment of the self-esteem need, individuals will be driven to seek it and unable to grow and obtain self-actualization. Maslow also states that the healthiest expression of self-esteem "is the one which manifests in the respect we deserve for others, more than renown, fame, and flattery". Modern theories of self-esteem explore the reasons humans are motivated to maintain a high regard for themselves. Sociometer theory maintains that self-esteem evolved to check one's level of status and acceptance in one's social group. According to Terror Management Theory, self-esteem serves a protective function and reduces anxiety about life and death.

Carl Rogers (1902–1987), an advocate of humanistic psychology, theorized the origin of many people's problems to be that they despise themselves and consider themselves worthless and incapable of being loved. This is why Rogers believed in the importance of giving unconditional acceptance to a client and when this was done it could improve the client's self-esteem. In his therapy sessions with clients, he offered positive regard no matter what. Indeed, the concept of self-esteem is approached since then in humanistic psychology as an inalienable right for every person, summarized in the following sentence:

Every human being, with no exception, for the mere fact to be it, is worthy of unconditional respect of everybody else; he deserves to esteem himself and to be esteemed.

Measurement

Self-esteem is typically assessed using self-report inventories.

One of the most widely used instruments, the Rosenberg self-esteem scale (RSES) is a 10-item self-esteem scale score that requires participants to indicate their level of agreement with a series of statements about themselves. An alternative measure, the Coopersmith Inventory uses a 50-question battery over a variety of topics and asks subjects whether they rate someone as similar or dissimilar to themselves. If a subject's answers demonstrate solid self-regard, the scale regards them as well adjusted. If those answers reveal some inner shame, it considers them to be prone to social deviance.

Implicit measures of self-esteem began to be used in the 1980s. These rely on indirect measures of cognitive processing thought to be linked to implicit self-esteem, including the name letter task (or initial preference task) and the Implicit Association Task.

Such indirect measures are designed to reduce awareness of the process of assessment. When using them to assess implicit self-esteem, psychologists apply self-relevant stimuli to the participant and then measure how quickly a person identifies positive or negative stimuli. For example, if a woman was given the self-relevant stimuli of female and mother, psychologists would measure how quickly she identified the negative word, evil, or the positive word, kind.

Development across lifespan

Experiences in a person's life are a major source of how self-esteem develops. In the early years of a child's life, parents have a significant influence on self-esteem and can be considered the main source of positive and negative experiences a child will have. Unconditional love from parents helps a child develop a stable sense of being cared for and respected. These feelings translate into later effects on self-esteem as the child grows older. Students in elementary school who have high self-esteem tend to have authoritative parents who are caring, supportive adults who set clear standards for their child and allow them to voice their opinion in decision making.

Although studies thus far have reported only a correlation of warm, supportive parenting styles (mainly authoritative and permissive) with children having high self-esteem, these parenting styles could easily be thought of as having some causal effect in self-esteem development. Childhood experiences that contribute to healthy self-esteem include being listened to, being spoken to respectfully, receiving appropriate attention and affection and having accomplishments recognized and mistakes or failures acknowledged and accepted. Experiences that contribute to low self-esteem include being harshly criticized, being physically, sexually or emotionally abused, being ignored, ridiculed or teased or being expected to be "perfect" all the time.

During school-aged years, academic achievement is a significant contributor to self-esteem development. Consistently achieving success or consistently failing will have a strong effect on students' individual self-esteem. However, students can also experience low self-esteem while in school. For example, they may not have academic achievements, or they live in a troubled environment outside of school. Issues like the ones previously stated, can cause adolescents to doubt themselves. Social experiences are another important contributor to self-esteem. As children go through school, they begin to understand and recognize differences between themselves and their classmates. Using social comparisons, children assess whether they did better or worse than classmates in different activities. These comparisons play an important role in shaping the child's self-esteem and influence the positive or negative feelings they have about themselves. As children go through adolescence, peer influence becomes much more important. Adolescents make appraisals of themselves based on their relationships with close friends. Successful relationships among friends are very important to the development of high self-esteem for children. Social acceptance brings about confidence and produces high self-esteem, whereas rejection from peers and loneliness brings about self-doubts and produces low self-esteem.

Self-esteem tends to increase during adolescence and young adulthood, reaching a peak in middle age. A decrease is seen from middle age to old age with varying findings on whether it is a small or large decrease. Reasons for the variability could be because of differences in health, cognitive ability, and socioeconomic status in old age. No differences have been found between males and females in their development of self-esteem. Multiple cohort studies show that there is not a difference in the life-span trajectory of self-esteem between generations due to societal changes such as grade inflation in education or the presence of social media.

High levels of mastery, low risk taking, and better health are ways to predict higher self-esteem. In terms of personality, emotionally stable, extroverted, and conscientious individuals experience higher self-esteem. These predictors have shown us that self-esteem has trait-like qualities by remaining stable over time like personality and intelligence. However, this does not mean it can not be changed. Hispanic adolescents have a slightly lower self-esteem than their black and white peers, but then slightly higher levels by age 30. African Americans have a sharper increase in self-esteem in adolescence and young adulthood compared to Whites. However, during old age, they experience a more rapid decline in self-esteem.

Shame

Shame can be a contributor to those with problems of low self-esteem. Feelings of shame usually occur because of a situation where the social self is devalued, such as a socially evaluated poor performance. Poor performance leads to a decrease in social self-esteem and an increase in shame, indicating a threat to the social self. This increase in shame can be helped with self-compassion.

Real self, ideal self, and dreaded self

There are three levels of self-evaluation development in relation to the real self, ideal self, and the dreaded self. The real, ideal, and dreaded selves develop in children in a sequential pattern on cognitive levels.

Moral judgment stages: Individuals describe their real, ideal, and dreaded selves with stereotypical labels, such as "nice" or "bad". Individuals describe their ideal and real selves in terms of disposition for actions or as behavioral habits. The dreaded self is often described as being unsuccessful or as having bad habits.
Ego development stages: Individuals describe their ideal and real selves in terms of traits that are based on attitudes as well as actions. The dreaded self is often described as having failed to meet social expectations or as self-centered.
Self-understanding stages: Individuals describe their ideal and real selves as having unified identities or characters. Descriptions of the dreaded self focus on failure to live up to one's ideals or role expectations often because of real world problems.

This development brings with it increasingly complicated and encompassing moral demands. This level is where individuals' self-esteems can suffer because they do not feel as though they are living up to certain expectations. This feeling will moderately affect one's self-esteem with an even larger effect seen when individuals believe they are becoming their dreaded selves.

Types

High

People with a healthy level of self-esteem:

firmly believe in certain values and principles, and are ready to defend them even when finding opposition, feeling secure enough to modify them in light of experience.
are able to act according to what they think to be the best choice, trusting their own judgment, and not feeling guilty when others do not like their choice.
do not lose time worrying excessively about what happened in the past, nor about what could happen in the future. They learn from the past and plan for the future, but live in the present intensely.
fully trust in their capacity to solve problems, not hesitating after failures and difficulties. They ask others for help when they need it.
consider themselves equal in dignity to others, rather than inferior or superior, while accepting differences in certain talents, personal prestige or financial standing.
understand how they are an interesting and valuable person for others, at least for those with whom they have a friendship.
resist manipulation, collaborate with others only if it seems appropriate and convenient.
admit and accept different internal feelings and drives, either positive or negative, revealing those drives to others only when they choose.
are able to enjoy a great variety of activities.
are sensitive to feelings and needs of others; respect generally accepted social rules, and claim no right or desire to prosper at others' expense.
can work toward finding solutions and voice discontent without belittling themselves or others when challenges arise.

Secure vs. defensive

Some people have a secure high self-esteem and can confidently maintain positive self-views without relying on external reassurance. However, others have defensive high self-esteem, and while they also report positive self-views on the Rosenberg Scale, these views are fragile and easily threatened by criticism. Defensive high self-esteem individuals internalize subconscious self-doubts and insecurities, causing them to react very negatively to any criticism they may receive. There is a need for constant positive feedback from others for these individuals to maintain their feelings of self-worth. The necessity of repeated praise can be associated with boastful, arrogant behavior or sometimes even aggressive and hostile feelings toward anyone who questions the individual's self-worth, an example of threatened egotism.

The Journal of Educational Psychology conducted a study in which they used a sample of 383 Malaysian undergraduates participating in work integrated learning (WIL) programs across five public universities to test the relationship between self-esteem and other psychological attributes such as self-efficacy and self-confidence. The results demonstrated that self-esteem has a positive and significant relationship with self-confidence and self-efficacy since students with higher self-esteem had better performances at university than those with lower self-esteem. It was concluded that higher education institutions and employers should emphasize the importance of undergraduates' self-esteem development.

Implicit and explicit

Implicit self-esteem refers to a person's disposition to evaluate themselves positively or negatively in a spontaneous, automatic, or unconscious manner. It contrasts with explicit self-esteem, which entails more conscious and reflective self-evaluation. Both explicit self-esteem and implicit self-esteem are theoretically subtypes of self-esteem proper.

However, the validity of implicit self-esteem as a construct is highly questionable, given not only its weak or nonexistent correlation with explicit self-esteem and informant ratings of self-esteem,but also the failure of multiple measures of implicit self-esteem to correlate with each other.

Currently, there is little scientific evidence that self-esteem can be reliably or validly measured through implicit means.

Narcissism and threatened egotism

Narcissism is a disposition people may have that represents an excessive love for one's self. It is characterized by an inflated view of self-worth. Individuals who score high on narcissism measures, Robert Raskin's Narcissistic Personality Inventory, would likely respond "true" to such prompt statements as "If I ruled the world, it would be a much better place." There is only a moderate correlation between narcissism and self-esteem; that is to say that an individual can have high self-esteem but low narcissism or can be a conceited, obnoxious person and score high self-esteem and high narcissism. However, when correlation analysis is restricted to the sense of superiority or self-admiration aspects of narcissism, correlations between narcissism and self-esteem become strong (usually at or around r = .50, but sometimes up to β = .86). Moreover, self-esteem is positively correlated with a sense of superiority even when controlling for overall narcissism.

Narcissism is not only defined by inflated self-esteem, but also by characteristics such as entitlement, exploitativeness, and dominance. Additionally, while positive self-image is a shared characteristic of narcissism and self-esteem, narcissistic self-appraisals are exaggerated, whereas in non-narcissistic self-esteem, positive views of the self compared with others are relatively modest. Thus, while sharing positive self-regard as a main feature, and while narcissism is defined by high self-esteem, the two constructs are not interchangeable.

Threatened egotism is a phenomenon in which narcissists respond to criticism with hostility and aggression, as it threatens their sense of self-worth.

Low

Low self-esteem can result from various factors, including genetic factors, physical appearance or weight, mental health issues, socioeconomic status, significant emotional experiences, social stigma, peer pressure or bullying.

A person with low self-esteem may show some of the following characteristics:

Heavy self-criticism and dissatisfaction.
Hypersensitivity to criticism with resentment against critics and feelings of being attacked.
Chronic indecision and an exaggerated fear of mistakes.
Excessive will to please and unwillingness to displease any petitioner.
Perfectionism, which can lead to frustration when perfection is not achieved.
Neurotic guilt, dwelling on or exaggerating the magnitude of past mistakes.
Floating hostility and general defensiveness and irritability without any proximate cause.
Pessimism and a general negative outlook.
Envy, invidiousness, or general resentment.
Sees temporary setbacks as permanent, intolerable conditions.

Individuals with low self-esteem tend to be critical of themselves. Some depend on the approval and praise of others when evaluating self-worth. Others may measure their likability in terms of successes: others will accept themselves if they succeed but will not if they fail. People with chronic low self esteem are at a higher risk for experiencing psychotic disorders; and this behavior is closely linked to forming psychotic symptoms as well.

Treatments

Metacognitive therapy, EMDR technique, mindfulness-based cognitive therapy, rational emotive behavior therapy, cognitive behavioral therapy and trait and construct therapies have been shown to improve the patient's self-esteem.

The three states

This classification proposed by Martin Ross distinguishes three states of self-esteem compared to the "feats" (triumphs, honors, virtues) and the "anti-feats" (defeats, embarrassment, shame, etc.) of the individuals.

Shattered

The individual does not regard themselves as valuable or lovable. They may be overwhelmed by defeat, or shame, or see themselves as such, and they name their "anti-feat". For example, if they consider that being over a certain age is an anti-feat, they define themselves with the name of their anti-feat, and say, "I am old". They express actions and feelings such as pity, insulting themselves, and they may become paralyzed by their sadness.

Vulnerable

The individual has a generally positive self-image. However, their self-esteem is also vulnerable to the perceived risk of an imminent anti-feat (such as defeat, embarrassment, shame, discredit), consequently, they are often nervous and regularly use defense mechanisms. A typical protection mechanism of those with vulnerable self-esteem may consist in avoiding decision-making. Although such individuals may outwardly exhibit great self-confidence, the underlying reality may be just the opposite: the apparent self-confidence is indicative of their heightened fear of anti-feats and the fragility of their self-esteem. They may also try to blame others to protect their self-image from situations that would threaten it. They may employ defense mechanisms, including attempting to lose at games and other competitions in order to protect their self-image by publicly dissociating themselves from a need to win, and asserting an independence from social acceptance which they may deeply desire. In this deep fear of being unaccepted by an individual's peers, they make poor life choices by making risky decisions.

Strong

People with strong self-esteem have a positive self-image and enough strength so that anti-feats do not subdue their self-esteem. They have less fear of failure. These individuals appear humble, cheerful, and this shows a certain strength not to boast about feats and not to be afraid of anti-feats. They are capable of fighting with all their might to achieve their goals because, if things go wrong, their self-esteem will not be affected. They can acknowledge their own mistakes precisely because their self-image is strong, and this acknowledgment will not impair or affect their self-image. They live with less fear of losing social prestige, and with more happiness and general well-being. However, no type of self-esteem is indestructible, and due to certain situations or circumstances in life, one can fall from this level into any other state of self-esteem.

Contingent vs. non-contingent

A distinction is made between contingent (or conditional) and non-contingent (or unconditional) self-esteem.

Contingent self-esteem is derived from external sources, such as what others say, one's success or failure, one's competence, or relationship-contingent self-esteem.

Therefore, contingent self-esteem is marked by instability, unreliability, and vulnerability. Persons lacking a non-contingent self-esteem are "predisposed to an incessant pursuit of self-value". However, because the pursuit of contingent self-esteem is based on receiving approval, it is doomed to fail, as no one receives constant approval, and disapproval often evokes depression. Furthermore, fear of disapproval inhibits activities in which failure is possible.

"The courage to be is the courage to accept oneself, in spite of being unacceptable.... This is the Pauline-Lutheran doctrine of 'justification by faith.'" Paul Tillich

Non-contingent self-esteem is described as true, stable, and solid. It springs from a belief that one is "acceptable period, acceptable before life itself, ontologically acceptable". Belief that one is "ontologically acceptable" is to believe that one's acceptability is "the way things are without contingency". In this belief, as expounded by theologian Paul Tillich, acceptability is not based on a person's virtue. It is an acceptance given "in spite of our guilt, not because we have no guilt".

Psychiatrist Thomas A Harris drew on Tillich for his classic I'm OK – You're OK that addresses non-contingent self-esteem. Harris translated Tillich's "acceptable" by the vernacular OK, a term that means "acceptable". The Christian message, said Harris, is not "YOU CAN BE OK, IF"; it is "YOU ARE ACCEPTED, unconditionally".

A secure non-contingent self-esteem springs from the belief that one is ontologically acceptable and accepted.

Domain-specific self-esteem

Whereas global self-esteem addresses how individuals appraise themselves in their entirety, domain-specific self-esteem facets relate to how they appraise themselves in various pertinent domains of life. Such functionally distinct facets of self-esteem may comprise self-evaluations in social, emotional, body-related, school performance-related, and creative-artistic domains.

They have been found to be predictive of outcomes related to psychological functioning, health, education, and work. Low self-esteem in the social domain (i.e., self-perceived social competence), for example, has been repeatedly identified as a risk factor for bullying victimization.

Importance

Abraham Maslow states that psychological health is not possible unless the essential core of the person is fundamentally accepted, loved and respected by others and by oneself. Self-esteem allows people to face life with more confidence, benevolence, and optimism, and thus easily reach their goals and self-actualize.

Self-esteem may make people convinced they deserve happiness. The ability to understand and develop positive self-esteem is essential for building healthy relationships with others. When people have a positive view of themselves, they are more likely to treat others with respect, compassion, and kindness. This creates the foundation for strong, positive relationships that are built on mutual respect and understanding. For Erich Fromm, the love of others and love of ourselves are not alternatives. On the contrary, an attitude of love toward themselves will be found in all those who are capable of loving others. Self-esteem allows creativity at the workplace and is a specially critical condition for teaching professions.

José-Vicente Bonet claims that the importance of self-esteem is obvious as a lack of self-esteem is, he says, not a loss of esteem from others, but self-rejection. Bonet claims that this corresponds to major depressive disorder. Freud also claimed that the depressive has suffered "an extraordinary diminution in his self-regard, an impoverishment of his ego on a grand scale... He has lost his self-respect".

The Yogyakarta Principles, a document on international human rights law, addresses the discriminatory attitude toward LGBT people that makes their self-esteem low to be subject to human rights violation including human trafficking. The World Health Organization recommends in "Preventing Suicide", published in 2000, that strengthening students' self-esteem is important to protect children and adolescents against mental distress and despondency, enabling them to cope adequately with difficult and stressful life situations.

Not only does higher self-esteem increase happiness, but it is also associated with improved stress coping and increased willingness to take on challenging tasks. In contrast, a study examined the impact of boosting self-esteem. It found that high self-esteem does offer some benefits, but they are limited. It is often a result, rather than a cause, of success. The researchers also found that efforts to boost self-esteem may not consistently lead to improved performance, and that self-esteem's influence on life outcomes is modest, except for a temporary increase in positive self-image awareness.

Correlations

From the late 1970s to the early 1990s many Americans assumed as a matter of course that students' self-esteem acted as a critical factor in the grades that they earned in school, in their relationships with their peers, and in their later success in life. Under this assumption, some American groups created programs which aimed to increase the self-esteem of students. Until the 1990s, little peer-reviewed and controlled research took place on this topic.

Peer-reviewed research undertaken since then has not validated previous assumptions. Recent research indicates that inflating students' self-esteems in and of itself has no positive effect on grades. Roy Baumeister has shown that inflating self-esteem by itself can actually decrease grades. The relationship involving self-esteem and academic results does not signify that high self-esteem contributes to high academic results. It simply means that high self-esteem may be accomplished as a result of high academic performance due to the other variables of social interactions and life events affecting this performance.

Attempts by pro-esteem advocates to encourage self-pride in students solely by reason of their uniqueness as human beings will fail if feelings of well-being are not accompanied by well-doing. It is only when students engage in personally meaningful endeavors for which they can be justifiably proud that self-confidence grows, and it is this growing self-assurance that in turn triggers further achievement.

Research has found a strong correlation between high self-esteem and self-reported happiness, but it is not yet known whether this relationship is causal. This means that although people with high self-esteem tend to report greater happiness, it is not certain whether having high self-esteem directly causes increased happiness. The relationship between self-esteem and life satisfaction is stronger in individualistic cultures.

In addition, people with high self-esteem have been found to be more forgiving than people with low self-esteem. This is because people with high self-esteem tend to have greater self-acceptance and are more likely to view conflict in a positive light, as an opportunity for growth and improvement. In contrast, people with low self-esteem may have a harder time forgiving others, due to a sense of insecurity and self-doubt.

High self-esteem does not prevent children from smoking, drinking, taking drugs, or engaging in early sex.

Mental health

Self-esteem has been associated with several mental health conditions, including depression, anxiety, and eating disorders. For example, low self-esteem may increase the likelihood that people who experience dysfunctional thoughts will develop symptoms of depression. Consequently, cognitive treatment of depression helps with low self-esteem, and vice versa, addressing low self-esteem improves depressive symptoms. In contrast, high self-esteem may protect against the development of mental health conditions, with research finding that high self-esteem reduces the chances of bulimia and anxiety.

Neuroscience

In research conducted in 2014 by Robert S. Chavez and Todd F. Heatherton, it was found that self-esteem is related to the connectivity of the frontostriatal circuit. The frontostriatal pathway connects the medial prefrontal cortex, which deals with self-knowledge, to the ventral striatum, which deals with feelings of motivation and reward. Stronger anatomical pathways are correlated with higher long-term self-esteem, while stronger functional connectivity is correlated with higher short-term self-esteem.

Criticism and controversy

Albert Ellis, an influential American psychologist, argued that the concept of self-esteem is actually harmful and unhelpful. Although acknowledging the human propensity and tendency to ego rating as innate, he has critiqued the philosophy of self-esteem as unrealistic, illogical and self- and socially destructive – often doing more harm than good. Questioning the foundations and usefulness of generalized ego strength, he has claimed that self-esteem is based on arbitrary definitional premises, and overgeneralized, perfectionistic and grandiose thinking. Acknowledging that rating and valuing behaviors and characteristics is functional and even necessary, he sees rating and valuing human beings' totality and total selves as irrational and unethical. The healthier alternative to self-esteem according to him is unconditional self-acceptance and unconditional other-acceptance. Rational Emotive Behavior Therapy is a psychotherapy based on this approach.

"There seem to be only two clearly demonstrated benefits of high self-esteem....First, it increases initiative, probably because it lends confidence. People with high self-esteem are more willing to act on their beliefs, to stand up for what they believe in, to approach others, to risk new undertakings. (This unfortunately includes being extra willing to do stupid or destructive things, even when everyone else advises against them.)...It can also lead people to ignore sensible advice as they stubbornly keep wasting time and money on hopeless causes"

False attempts

For persons with low self-esteem, any positive stimulus will temporarily raise self-esteem. Therefore, possessions, sex, success, or physical appearance will produce the development of self-esteem, but the development is ephemeral at best. Such attempts to raise one's self-esteem by positive stimulus produce a "boom or bust" pattern. "Compliments and positive feedback" produce a boost, but a bust follows a lack of such feedback. For a person whose "self-esteem is contingent", success is "not extra sweet", but "failure is extra bitter".

As narcissism

Life satisfaction, happiness, healthy behavioral practices, perceived efficacy, and academic success and adjustment have been associated with having high levels of self-esteem. However, a common mistake is to think that loving oneself is necessarily equivalent to narcissism, as opposed for example to what Erik Erikson speaks of as "a post-narcissistic love of the ego". People with healthy self-esteem accept and love themselves unconditionally, acknowledging both virtues and faults in the self, and yet, in spite of everything, are able to continue to love themselves. In narcissists, by contrast, an "uncertainty about their own worth gives rise to...a self-protective, but often totally spurious, aura of grandiosity" – producing the class "of narcissists, or people with very high, but insecure, self-esteem... fluctuating with each new episode of social praise or rejection." For narcissists, regulating their self-esteem is their constant concern. They use defenses (such as denial, projection, self-inflation, envy, arrogance, and aggression), impression management through self-promotion, embellishment, lying, charm, and domination, and prefer high-status, competitive, and hierarchical environments to support their unstable, fragile, and impaired self-esteem.

Narcissism can thus be seen as a symptom of fundamentally low self-esteem, that is, lack of love towards oneself, but often accompanied by "an immense increase in self-esteem" based on "the defense mechanism of denial by overcompensation." "Idealized love of self...rejected the part of him" that he denigrates – "this destructive little child" within. Instead, the narcissist emphasizes their virtues in the presence of others, just to try to convince themself that they are a valuable person and to try to stop feeling ashamed for their faults; such "people with unrealistically inflated self-views, which may be especially unstable and highly vulnerable to negative information,...tend to have poor social skills."

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Monday, May 6, 2024

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Self-esteem

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Shame

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Secure vs. defensive

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The three states

Shattered

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Contingent vs. non-contingent