Semiconductor

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Semiconductor

 

A semiconductor material has an electrical conductivity value falling between that of a conductor, such as metallic copper, and an insulator, such as glass. Its resistance falls as its temperature rises; metals are the opposite. Its conducting properties may be altered in useful ways by introducing impurities ("doping") into the crystal structure. Where two differently-doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers which include electrons, ions and electron holes at these junctions is the basis of diodes, transistors and all modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits and others. Silicon is a critical element for fabricating most electronic circuits.

Semiconductor devices can display a range of useful properties such as passing current more easily in one direction than the other, showing variable resistance, and sensitivity to light or heat. Because the electrical properties of a semiconductor material can be modified by doping, or by the application of electrical fields or light, devices made from semiconductors can be used for amplification, switching, and energy conversion.

The conductivity of silicon is increased by adding a small amount (of the order of 1 in 10⁸) of pentavalent (antimony, phosphorus, or arsenic) or trivalent (boron, gallium, indium) atoms. This process is known as doping and resulting semiconductors are known as doped or extrinsic semiconductors. Apart from doping, the conductivity of a semiconductor can equally be improved by increasing its temperature. This is contrary to the behaviour of a metal in which conductivity decreases with increase in temperature.

The modern understanding of the properties of a semiconductor relies on quantum physics to explain the movement of charge carriers in a crystal lattice. Doping greatly increases the number of charge carriers within the crystal. When a doped semiconductor contains mostly free holes it is called "p-type", and when it contains mostly free electrons it is known as "n-type". The semiconductor materials used in electronic devices are doped under precise conditions to control the concentration and regions of p- and n-type dopants. A single semiconductor crystal can have many p- and n-type regions; the p–n junctions between these regions are responsible for the useful electronic behavior.

Some of the properties of semiconductor materials were observed throughout the mid 19th and first decades of the 20th century. The first practical application of semiconductors in electronics was the 1904 development of the cat's-whisker detector, a primitive semiconductor diode used in early radio receivers. Developments in quantum physics in turn led to the development of the transistor in 1947, the integrated circuit in 1958, and the MOSFET (metal–oxide–semiconductor field-effect transistor) in 1959.

Properties

Variable electrical conductivity

Semiconductors in their natural state are poor conductors because a current requires the flow of electrons, and semiconductors have their valence bands filled, preventing the entire flow of new electrons. There are several developed techniques that allow semiconducting materials to behave like conducting materials, such as doping or gating. These modifications have two outcomes: n-type and p-type. These refer to the excess or shortage of electrons, respectively. An unbalanced number of electrons would cause a current to flow through the material.

Heterojunctions

Heterojunctions occur when two differently doped semiconducting materials are joined together. For example, a configuration could consist of p-doped and n-doped germanium. This results in an exchange of electrons and holes between the differently doped semiconducting materials. The n-doped germanium would have an excess of electrons, and the p-doped germanium would have an excess of holes. The transfer occurs until equilibrium is reached by a process called recombination, which causes the migrating electrons from the n-type to come in contact with the migrating holes from the p-type. A product of this process is charged ions, which result in an electric field.

Excited electrons

A difference in electric potential on a semiconducting material would cause it to leave thermal equilibrium and create a non-equilibrium situation. This introduces electrons and holes to the system, which interact via a process called ambipolar diffusion. Whenever thermal equilibrium is disturbed in a semiconducting material, the number of holes and electrons changes. Such disruptions can occur as a result of a temperature difference or photons, which can enter the system and create electrons and holes. The process that creates and annihilates electrons and holes are called generation and recombination.

Light emission

In certain semiconductors, excited electrons can relax by emitting light instead of producing heat. These semiconductors are used in the construction of light-emitting diodes and fluorescent quantum dots.

High thermal conductivity

Semiconductors with high thermal conductivity can be used for heat dissipation and improving thermal management of electronics.

Thermal energy conversion

Semiconductors have large thermoelectric power factors making them useful in thermoelectric generators, as well as high thermoelectric figures of merit making them useful in thermoelectric coolers.

Materials

Silicon crystals are the most common semiconducting materials used in microelectronics and photovoltaics.

A large number of elements and compounds have semiconducting properties, including:

• Certain pure elements are found in Group 14 of the periodic table; the most commercially important of these elements are silicon and germanium. Silicon and germanium are used here effectively because they have 4 valence electrons in their outermost shell which gives them the ability to gain or lose electrons equally at the same time.
• Binary compounds, particularly between elements in Groups 13 and 15, such as gallium arsenide, Groups 12 and 16, groups 14 and 16, and between different group 14 elements, e.g. silicon carbide.
• Certain ternary compounds, oxides and alloys.
• Organic semiconductors, made of organic compounds.

Most common semiconducting materials are crystalline solids, but amorphous and liquid semiconductors are also known. These include hydrogenated amorphous silicon and mixtures of arsenic, selenium and tellurium in a variety of proportions. These compounds share with better known semiconductors the properties of intermediate conductivity and a rapid variation of conductivity with temperature, as well as occasional negative resistance. Such disordered materials lack the rigid crystalline structure of conventional semiconductors such as silicon. They are generally used in thin film structures, which do not require material of higher electronic quality, being relatively insensitive to impurities and radiation damage.

Preparation of semiconductor materials

Almost all of today's electronic technology involves the use of semiconductors, with the most important aspect being the integrated circuit (IC), which are found in laptops, scanners, cell-phones, etc. Semiconductors for ICs are mass-produced. To create an ideal semiconducting material, chemical purity is paramount. Any small imperfection can have a drastic effect on how the semiconducting material behaves due to the scale at which the materials are used.

A high degree of crystalline perfection is also required, since faults in crystal structure (such as dislocations, twins, and stacking faults) interfere with the semiconducting properties of the material. Crystalline faults are a major cause of defective semiconductor devices. The larger the crystal, the more difficult it is to achieve the necessary perfection. Current mass production processes use crystal ingots between 100 and 300 mm (3.9 and 11.8 in) in diameter which are grown as cylinders and sliced into wafers.

There is a combination of processes that is used to prepare semiconducting materials for ICs. One process is called thermal oxidation, which forms silicon dioxide on the surface of the silicon. This is used as a gate insulator and field oxide. Other processes are called photomasks and photolithography. This process is what creates the patterns on the circuity in the integrated circuit. Ultraviolet light is used along with a photoresist layer to create a chemical change that generates the patterns for the circuit.

Etching is the next process that is required. The part of the silicon that was not covered by the photoresist layer from the previous step can now be etched. The main process typically used today is called plasma etching. Plasma etching usually involves an etch gas pumped in a low-pressure chamber to create plasma. A common etch gas is chlorofluorocarbon, or more commonly known Freon. A high radio-frequency voltage between the cathode and anode is what creates the plasma in the chamber. The silicon wafer is located on the cathode, which causes it to be hit by the positively charged ions that are released from the plasma. The end result is silicon that is etched anisotropically.

The last process is called diffusion. This is the process that gives the semiconducting material its desired semiconducting properties. It is also known as doping. The process introduces an impure atom to the system, which creates the p-n junction. In order to get the impure atoms embedded in the silicon wafer, the wafer is first put in a 1,100 degree Celsius chamber. The atoms are injected in and eventually diffuse with the silicon. After the process is completed and the silicon has reached room temperature, the doping process is done and the semiconducting material is ready to be used in an integrated circuit.

Physics of semiconductors

Energy bands and electrical conduction

Filling of the electronic states in various types of materials at equilibrium. Here, height is energy while width is the density of available states for a certain energy in the material listed. The shade follows the Fermi–Dirac distribution (black = all states filled, white = no state filled). In metals and semimetals the Fermi level E_F lies inside at least one band. In insulators and semiconductors the Fermi level is inside a band gap; however, in semiconductors the bands are near enough to the Fermi level to be thermally populated with electrons or holes

 

Semiconductors are defined by their unique electric conductive behavior, somewhere between that of a conductor and an insulator. The differences between these materials can be understood in terms of the quantum states for electrons, each of which may contain zero or one electron (by the Pauli exclusion principle). These states are associated with the electronic band structure of the material. Electrical conductivity arises due to the presence of electrons in states that are delocalized (extending through the material), however in order to transport electrons a state must be partially filled, containing an electron only part of the time. If the state is always occupied with an electron, then it is inert, blocking the passage of other electrons via that state. The energies of these quantum states are critical, since a state is partially filled only if its energy is near the Fermi level.

High conductivity in a material comes from it having many partially filled states and much state delocalization. Metals are good electrical conductors and have many partially filled states with energies near their Fermi level. Insulators, by contrast, have few partially filled states, their Fermi levels sit within band gaps with few energy states to occupy. Importantly, an insulator can be made to conduct by increasing its temperature: heating provides energy to promote some electrons across the band gap, inducing partially filled states in both the band of states beneath the band gap (valence band) and the band of states above the band gap (conduction band). An (intrinsic) semiconductor has a band gap that is smaller than that of an insulator and at room temperature significant numbers of electrons can be excited to cross the band gap.

A pure semiconductor, however, is not very useful, as it is neither a very good insulator nor a very good conductor. However, one important feature of semiconductors (and some insulators, known as semi-insulators) is that their conductivity can be increased and controlled by doping with impurities and gating with electric fields. Doping and gating move either the conduction or valence band much closer to the Fermi level, and greatly increase the number of partially filled states.

Some wider-band gap semiconductor materials are sometimes referred to as semi-insulators. When undoped, these have electrical conductivity nearer to that of electrical insulators, however they can be doped (making them as useful as semiconductors). Semi-insulators find niche applications in micro-electronics, such as substrates for HEMT. An example of a common semi-insulator is gallium arsenide. Some materials, such as titanium dioxide, can even be used as insulating materials for some applications, while being treated as wide-gap semiconductors for other applications.

Charge carriers (electrons and holes)

The partial filling of the states at the bottom of the conduction band can be understood as adding electrons to that band. The electrons do not stay indefinitely (due to the natural thermal recombination) but they can move around for some time. The actual concentration of electrons is typically very dilute, and so (unlike in metals) it is possible to think of the electrons in the conduction band of a semiconductor as a sort of classical ideal gas, where the electrons fly around freely without being subject to the Pauli exclusion principle. In most semiconductors the conduction bands have a parabolic dispersion relation, and so these electrons respond to forces (electric field, magnetic field, etc.) much like they would in a vacuum, though with a different effective mass. Because the electrons behave like an ideal gas, one may also think about conduction in very simplistic terms such as the Drude model, and introduce concepts such as electron mobility.

For partial filling at the top of the valence band, it is helpful to introduce the concept of an electron hole. Although the electrons in the valence band are always moving around, a completely full valence band is inert, not conducting any current. If an electron is taken out of the valence band, then the trajectory that the electron would normally have taken is now missing its charge. For the purposes of electric current, this combination of the full valence band, minus the electron, can be converted into a picture of a completely empty band containing a positively charged particle that moves in the same way as the electron. Combined with the negative effective mass of the electrons at the top of the valence band, we arrive at a picture of a positively charged particle that responds to electric and magnetic fields just as a normal positively charged particle would do in vacuum, again with some positive effective mass. This particle is called a hole, and the collection of holes in the valence band can again be understood in simple classical terms (as with the electrons in the conduction band). 

Carrier generation and recombination

When ionizing radiation strikes a semiconductor, it may excite an electron out of its energy level and consequently leave a hole. This process is known as electron–hole pair generation. Electron-hole pairs are constantly generated from thermal energy as well, in the absence of any external energy source.

Electron-hole pairs are also apt to recombine. Conservation of energy demands that these recombination events, in which an electron loses an amount of energy larger than the band gap, be accompanied by the emission of thermal energy (in the form of phonons) or radiation (in the form of photons).

In some states, the generation and recombination of electron–hole pairs are in equipoise. The number of electron-hole pairs in the steady state at a given temperature is determined by quantum statistical mechanics. The precise quantum mechanical mechanisms of generation and recombination are governed by conservation of energy and conservation of momentum.

As the probability that electrons and holes meet together is proportional to the product of their numbers, the product is in steady state nearly constant at a given temperature, providing that there is no significant electric field (which might "flush" carriers of both types, or move them from neighbour regions containing more of them to meet together) or externally driven pair generation. The product is a function of the temperature, as the probability of getting enough thermal energy to produce a pair increases with temperature, being approximately exp(−E_G/kT), where k is Boltzmann's constant, T is absolute temperature and E_G is band gap.

The probability of meeting is increased by carrier traps—impurities or dislocations which can trap an electron or hole and hold it until a pair is completed. Such carrier traps are sometimes purposely added to reduce the time needed to reach the steady state.

Doping

The conductivity of semiconductors may easily be modified by introducing impurities into their crystal lattice. The process of adding controlled impurities to a semiconductor is known as doping. The amount of impurity, or dopant, added to an intrinsic (pure) semiconductor varies its level of conductivity. Doped semiconductors are referred to as extrinsic. By adding impurity to the pure semiconductors, the electrical conductivity may be varied by factors of thousands or millions.

A 1 cm³ specimen of a metal or semiconductor has of the order of 10²² atoms. In a metal, every atom donates at least one free electron for conduction, thus 1 cm³ of metal contains on the order of 10²² free electrons, whereas a 1 cm³ sample of pure germanium at 20 °C contains about 4.2×10²² atoms, but only 2.5×10¹³ free electrons and 2.5×10¹³ holes. The addition of 0.001% of arsenic (an impurity) donates an extra 10¹⁷ free electrons in the same volume and the electrical conductivity is increased by a factor of 10,000.

The materials chosen as suitable dopants depend on the atomic properties of both the dopant and the material to be doped. In general, dopants that produce the desired controlled changes are classified as either electron acceptors or donors. Semiconductors doped with donor impurities are called n-type, while those doped with acceptor impurities are known as p-type. The n and p type designations indicate which charge carrier acts as the material's majority carrier. The opposite carrier is called the minority carrier, which exists due to thermal excitation at a much lower concentration compared to the majority carrier.

For example, the pure semiconductor silicon has four valence electrons which bond each silicon atom to its neighbors. In silicon, the most common dopants are group III and group V elements. Group III elements all contain three valence electrons, causing them to function as acceptors when used to dope silicon. When an acceptor atom replaces a silicon atom in the crystal, a vacant state (an electron "hole") is created, which can move around the lattice and functions as a charge carrier. Group V elements have five valence electrons, which allows them to act as a donor; substitution of these atoms for silicon creates an extra free electron. Therefore, a silicon crystal doped with boron creates a p-type semiconductor whereas one doped with phosphorus results in an n-type material.

During manufacture, dopants can be diffused into the semiconductor body by contact with gaseous compounds of the desired element, or ion implantation can be used to accurately position the doped regions.

Amorphous semiconductors

Some materials, when rapidly cooled to a glassy amorphous state, have semiconducting properties. These include B, Si, Ge, Se, Te and there are multiple theories to explain them.

Early history of semiconductors

The history of the understanding of semiconductors begins with experiments on the electrical properties of materials. The properties of negative temperature coefficient of resistance, rectification, and light-sensitivity were observed starting in the early 19th century.

Karl Ferdinand Braun developed the crystal detector, the first semiconductor device, in 1874

 

Thomas Johann Seebeck was the first to notice an effect due to semiconductors, in 1821.^[15] In 1833, Michael Faraday reported that the resistance of specimens of silver sulfide decreases when they are heated. This is contrary to the behavior of metallic substances such as copper. In 1839, Alexandre Edmond Becquerel reported observation of a voltage between a solid and a liquid electrolyte when struck by light, the photovoltaic effect. In 1873 Willoughby Smith observed that selenium resistors exhibit decreasing resistance when light falls on them. In 1874, Karl Ferdinand Braun observed conduction and rectification in metallic sulfides, although this effect had been discovered much earlier by Peter Munck af Rosenschold writing for the Annalen der Physik und Chemie in 1835, and Arthur Schuster found that a copper oxide layer on wires has rectification properties that ceases when the wires are cleaned. William Grylls Adams and Richard Evans Day observed the photovoltaic effect in selenium in 1876.

A unified explanation of these phenomena required a theory of solid-state physics which developed greatly in the first half of the 20th Century. In 1878 Edwin Herbert Hall demonstrated the deflection of flowing charge carriers by an applied magnetic field, the Hall effect. The discovery of the electron by J.J. Thomson in 1897 prompted theories of electron-based conduction in solids. Karl Baedeker, by observing a Hall effect with the reverse sign to that in metals, theorized that copper iodide had positive charge carriers. Johan Koenigsberger classified solid materials as metals, insulators and "variable conductors" in 1914 although his student Josef Weiss already introduced the term Halbleiter (semiconductor in modern meaning) in PhD thesis in 1910. Felix Bloch published a theory of the movement of electrons through atomic lattices in 1928. In 1930, B. Gudden stated that conductivity in semiconductors was due to minor concentrations of impurities. By 1931, the band theory of conduction had been established by Alan Herries Wilson and the concept of band gaps had been developed. Walter H. Schottky and Nevill Francis Mott developed models of the potential barrier and of the characteristics of a metal–semiconductor junction. By 1938, Boris Davydov had developed a theory of the copper-oxide rectifier, identifying the effect of the p–n junction and the importance of minority carriers and surface states.

Agreement between theoretical predictions (based on developing quantum mechanics) and experimental results was sometimes poor. This was later explained by John Bardeen as due to the extreme "structure sensitive" behavior of semiconductors, whose properties change dramatically based on tiny amounts of impurities. Commercially pure materials of the 1920s containing varying proportions of trace contaminants produced differing experimental results. This spurred the development of improved material refining techniques, culminating in modern semiconductor refineries producing materials with parts-per-trillion purity.

Devices using semiconductors were at first constructed based on empirical knowledge, before semiconductor theory provided a guide to construction of more capable and reliable devices.

Alexander Graham Bell used the light-sensitive property of selenium to transmit sound over a beam of light in 1880. A working solar cell, of low efficiency, was constructed by Charles Fritts in 1883 using a metal plate coated with selenium and a thin layer of gold; the device became commercially useful in photographic light meters in the 1930s. Point-contact microwave detector rectifiers made of lead sulfide were used by Jagadish Chandra Bose in 1904; the cat's-whisker detector using natural galena or other materials became a common device in the development of radio. However, it was somewhat unpredictable in operation and required manual adjustment for best performance. In 1906 H.J. Round observed light emission when electric current passed through silicon carbide crystals, the principle behind the light-emitting diode. Oleg Losev observed similar light emission in 1922 but at the time the effect had no practical use. Power rectifiers, using copper oxide and selenium, were developed in the 1920s and became commercially important as an alternative to vacuum tube rectifiers.

The first semiconductor devices used galena, including German physicist Ferdinand Braun's crystal detector in 1874 and Bengali physicist Jagadish Chandra Bose's radio crystal detector in 1901.

In the years preceding World War II, infrared detection and communications devices prompted research into lead-sulfide and lead-selenide materials. These devices were used for detecting ships and aircraft, for infrared rangefinders, and for voice communication systems. The point-contact crystal detector became vital for microwave radio systems, since available vacuum tube devices could not serve as detectors above about 4000 MHz; advanced radar systems relied on the fast response of crystal detectors. Considerable research and development of silicon materials occurred during the war to develop detectors of consistent quality.

Early transistors

John Bardeen, William Shockley and Walter Brattain developed the bipolar point-contact transistor in 1947

 

Detector and power rectifiers could not amplify a signal. Many efforts were made to develop a solid-state amplifier and were successful in developing a device called the point contact transistor which could amplify 20db or more. In 1922 Oleg Losev developed two-terminal, negative resistance amplifiers for radio, and he perished in the Siege of Leningrad after successful completion. In 1926 Julius Edgar Lilienfeld patented a device resembling a field-effect transistor, but it was not practical. R. Hilsch and R. W. Pohl in 1938 demonstrated a solid-state amplifier using a structure resembling the control grid of a vacuum tube; although the device displayed power gain, it had a cut-off frequency of one cycle per second, too low for any practical applications, but an effective application of the available theory. At Bell Labs, William Shockley and A. Holden started investigating solid-state amplifiers in 1938. The first p–n junction in silicon was observed by Russell Ohl about 1941, when a specimen was found to be light-sensitive, with a sharp boundary between p-type impurity at one end and n-type at the other. A slice cut from the specimen at the p–n boundary developed a voltage when exposed to light.

The first working transistor was a point-contact transistor invented by John Bardeen, Walter Houser Brattain and William Shockley at Bell Labs in 1947. Shockley had earlier theorized a field-effect amplifier made from germanium and silicon, but he failed to build such a working device, before eventually using germanium to invent the point-contact transistor. In France, during the war, Herbert Mataré had observed amplification between adjacent point contacts on a germanium base. After the war, Mataré's group announced their "Transistron" amplifier only shortly after Bell Labs announced the "transistor".

In 1954, physical chemist Morris Tanenbaum fabricated the first silicon junction transistor at Bell Labs. However, early junction transistors were relatively bulky devices that were difficult to manufacture on a mass-production basis, which limited them to a number of specialised applications.

Silicon semiconductors

Mohamed Atalla developed the surface passivation process in 1957 and the MOS transistor in 1959

 

The first silicon semiconductor device was a silicon radio crystal detector, developed by American engineer Greenleaf Whittier Pickard in 1906. In 1940, Russell Ohl discovered the p-n junction and photovoltaic effects in silicon. In 1941, techniques for producing high-purity germanium and silicon crystals were developed for radar microwave detectors during World War II. In 1955, Carl Frosch and Lincoln Derick at Bell Labs accidentally discovered that silicon dioxide (SiO₂) could be grown on silicon, and they later proposed this could mask silicon surfaces during diffusion processes in 1958.

In the early years of the semiconductor industry, up until the late 1950s, germanium was the dominant semiconductor material for transistors and other semiconductor devices, rather than silicon. Germanium was initially considered the more effective semiconductor material, as it was able to demonstrate better performance due to higher carrier mobility. The relative lack of performance in early silicon semiconductors was due to electrical conductivity being limited by unstable quantum surface states, where electrons are trapped at the surface, due to dangling bonds that occur because unsaturated bonds are present at the surface. This prevented electricity from reliably penetrating the surface to reach the semiconducting silicon layer.

A breakthrough in silicon semiconductor technology came with the work of Egyptian engineer Mohamed Atalla, who developed the process of surface passivation by thermal oxidation at Bell Labs in the late 1950s. He discovered that the formation of a thermally grown silicon dioxide layer greatly reduced the concentration of electronic states at the silicon surface, and that silicon oxide layers could be used to electrically stabilize silicon surfaces. Atalla first published his findings in Bell memos during 1957, and then demonstrated it in 1958. This was the first demonstration to show that high-quality silicon dioxide insulator films could be grown thermally on the silicon surface to protect the underlying silicon p-n junction diodes and transistors. Atalla's surface passivation process enabled silicon to surpass the conductivity and performance of germanium, and led to silicon replacing germanium as the dominant semiconductor material. Atalla's surface passivation process is considered the most important advance in silicon semiconductor technology, paving the way for the mass-production of silicon semiconductor devices. By the mid-1960s, Atalla's process for oxidized silicon surfaces was used to fabricate virtually all integrated circuits and silicon devices. Surface passivation by thermal oxidation remains a key feature of silicon semiconductor technology.

MOSFET (MOS transistor)

The MOSFET (MOS transistor) was invented by Mohamed Atalla and Dawon Kahng in 1959

 

In the late 1950s, Mohamed Atalla utilized his surface passivation and thermal oxidation methods to develop the metal–oxide–semiconductor (MOS) process, which he proposed could be used to build the first working silicon field-effect transistor. This led to the invention of the MOSFET (MOS field-effect transistor) by Mohamed Atalla and Dawon Kahng in 1959. It was the first truly compact transistor that could be miniaturised and mass-produced for a wide range of uses, With its scalability, and much lower power consumption and higher density than bipolar junction transistors, the MOSFET became the most common type of transistor in computers, electronics, and communications technology such as smartphones. The US Patent and Trademark Office calls the MOSFET a "groundbreaking invention that transformed life and culture around the world".

The CMOS (complementary MOS) process was developed by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. The first report of a floating-gate MOSFET was made by Dawon Kahng and Simon Sze in 1967. FinFET (fin field-effect transistor), a type of 3D multi-gate MOSFET, was developed by Digh Hisamoto and his team of researchers at Hitachi Central Research Laboratory in 1989.

Imprinting (psychology)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Imprinting_(psychology)

 

In psychology and ethology, imprinting is any kind of phase-sensitive learning (learning occurring at a particular age or a particular life stage) that is rapid and apparently independent of the consequences of behaviour. It was first used to describe situations in which an animal or person learns the characteristics of some stimulus, which is therefore said to be "imprinted" onto the subject. Imprinting is hypothesized to have a critical period.

Filial imprinting

The best-known form of imprinting is filial imprinting, in which a young animal narrows its social preferences to an object (typically a parent) as a result of exposure to that object. It is most obvious in nidifugous birds, which imprint on their parents and then follow them around. It was first reported in domestic chickens, by Sir Thomas More in 1516 as described in his treatise Utopia, 350 earlier than by the 19th-century amateur biologist Douglas Spalding. It was rediscovered by the early ethologist Oskar Heinroth, and studied extensively and popularized by his disciple Konrad Lorenz working with greylag geese.

Lorenz demonstrated how incubator-hatched geese would imprint on the first suitable moving stimulus they saw within what he called a "critical period" between 13–16 hours shortly after hatching. For example, the goslings would imprint on Lorenz himself (to be more specific, on his wading boots), and he is often depicted being followed by a gaggle of geese who had imprinted on him. Lorenz also found that the geese could imprint on inanimate objects. In one notable experiment, they followed a box placed on a model train in circles around the track. Filial imprinting is not restricted to non-human animals that are able to follow their parents, however. 

The filial imprinting of birds was a primary technique used to create the movie Winged Migration (Le Peuple Migrateur), which contains a great deal of footage of migratory birds in flight. The birds imprinted on handlers, who wore yellow jackets and honked horns constantly. The birds were then trained to fly along with a variety of aircraft, primarily ultralights.

Imprinted geese and cranes flying with an ultralight aircraft

 

The Italian hang-glider pilot Angelo d'Arrigo extended this technique. D'Arrigo noted that the flight of a non-motorised hang-glider is very similar to the flight patterns of migratory birds; both use updrafts of hot air (thermal currents) to gain altitude that then permits soaring flight over distance. He used this to reintroduce threatened species of raptors. Because birds hatched in captivity have no mentor birds to teach them traditional migratory routes, D'Arrigo hatched chicks under the wing of his glider and imprinted on him. Then, he taught the fledglings to fly and to hunt. The young birds followed him not only on the ground (as with Lorenz) but also in the air as he took the path of various migratory routes. He flew across the Sahara and over the Mediterranean Sea to Sicily with eagles, from Siberia to Iran (5,500 km) with a flock of Siberian cranes, and over Mount Everest with Nepalese eagles. In 2006, he worked with a condor in South America.

In a similar project, orphaned Canada geese were trained to their normal migration route by the Canadian ultralight enthusiast Bill Lishman, as shown in the fact-based movie drama Fly Away Home.

Chicks of domestic chickens prefer to be near large groups of objects that they have imprinted on. This behaviour was used to determine that very young chicks of a few days old have rudimentary counting skills. In a series of experiments, they were made to imprint on plastic balls and could figure out which of two groups of balls hidden behind screens had the most balls.

American coot mothers have the ability to recognize their chicks by imprinting on cues from the first chick that hatches. This allows mothers to distinguish their chicks from parasitic chicks.

The peregrine falcon has also been known to imprint on specific structures for their breeding grounds such as cliff sides and bridges and thus will favour that location for breeding.

Sexual imprinting

Sexual imprinting is the process by which a young animal learns the characteristics of a desirable mate. For example, male zebra finches appear to prefer mates with the appearance of the female bird that rears them, rather than that of the birth parent when they are different.

Sexual attraction to humans can develop in non-human mammals or birds as a result of sexual imprinting when reared from young by humans. One example is London Zoo female giant panda Chi Chi. When taken to Moscow Zoo for mating with the male giant panda An An, she refused his attempts to mate with her, but made a full sexual self-presentation to a zookeeper.

It commonly occurs in falconry birds reared from hatching by humans. Such birds are called "imprints" in falconry. When an imprint must be bred from, the breeder lets the male bird copulate with their head while they are wearing a special hat with pockets on to catch the male bird's semen. The breeder then courts a suitable imprint female bird (including offering food, if it is part of that species's normal courtship). At "copulation," the breeder puts the flat of one hand on the female bird's back to represent the weight of a male bird, and with the other hand uses a pipette, or a hypodermic syringe without a needle, to squirt the semen into the female's cloaca.

Sexual imprinting on inanimate objects is a popular theory concerning the development of sexual fetishism. For example, according to this theory, imprinting on shoes or boots (as with Konrad Lorenz's geese) would be the cause of shoe fetishism.

Limbic imprinting

Some suggest that prenatal, perinatal and post-natal experiences leave imprints upon the limbic system, causing lifelong effects and this process is identified as limbic imprinting. The term is also described as the human emotional map, deep-seated beliefs, and values that are stored in the brain's limbic system and govern people's lives at the subconscious level. It is one of the suggested explanations for the claim that the experiences of an infant, particularly during the first two years of his life, contribute to his lifelong psychological development. Imprinted genes can have astounding effects on body size, brain size, and the process in which the brain organizes its processes. Evolutionary trends within the animal kingdom have been shown to show substantive increase in the fore-brain particularly towards the limbic system, this evolution has even been through of to have a mutative effect on the brain size trickling down the human ancestry.

Westermarck effect

Reverse sexual imprinting is also seen in instances where two people who live in domestic proximity during the first few years in the life of either one become desensitized to later close sexual attraction. This phenomenon, known as the Westermarck effect, was first formally described by Finnish anthropologist Edvard Westermarck in his book The History of Human Marriage (1891). The Westermarck effect has since been observed in many places and cultures, including in the Israeli kibbutz system, and the Chinese shim-pua marriage customs, as well as in biological-related families.

In the case of the Israeli kibbutzim (collective farms), children were reared somewhat communally in peer groups, based on age, not biological relation. A study of the marriage patterns of these children later in life revealed that out of the nearly 3,000 marriages that occurred across the kibbutz system, only fourteen were between children from the same peer group. Of those fourteen, none had been reared together during the first six years of life. This result provides evidence not only that the Westermarck effect is demonstrable but that it operates during the period from birth to the age of six. However, Eran Shor and Dalit Simchai claimed that the case of the kibbutzim actually provides little support for the Westermarck effect.

When proximity during this critical period does not occur—for example, where a brother and sister are brought up separately, never meeting one another—they may find one another highly sexually attractive when they meet as adults. This phenomenon is known as genetic sexual attraction. This observation supports the hypothesis that the Westermarck effect evolved because it suppressed inbreeding. This attraction may also be seen with cousin couples.

Sigmund Freud argued that as children, members of the same family naturally lust for one another, making it necessary for societies to create incest taboos, but Westermarck argued the reverse, that the taboos themselves arise naturally as products of innate attitudes. Steven Pinker has written that Freud's conception of an urge to incest may have derived from Freud's own erotic reaction to his mother as a boy (attested in Freud's own writings), and speculates that Freud's reaction may have been due to lack of intimacy with his mother in early childhood, as Freud was wet-nursed.

Baby duck syndrome

Ducklings following their mother.

 

In human–computer interaction, baby duck syndrome denotes the tendency for computer users to "imprint" on the first system they learn, then judge other systems by their similarity to that first system.  The result is that "users generally prefer systems similar to those they learned on and dislike unfamiliar systems". The issue may present itself relatively early in a computer user's experience, and it has been observed to impede education of students in new software systems or user interfaces.

Konrad Lorenz

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Konrad_Lorenz

 

Konrad Lorenz ForMemRS
Born	Konrad Zacharias Lorenz 7 November 1903 Vienna, Austria-Hungary
Died	27 February 1989 (aged 85) Vienna, Austria
Nationality	Austrian
Awards	ForMemRS (1964) Kalinga Prize (1969) Nobel Prize in Physiology or Medicine (1973)
Scientific career
Fields	Ethology

Konrad Zacharias Lorenz (German pronunciation: [ˈkɔnʁaːt ˈloːʁɛnts]; 7 November 1903 – 27 February 1989) was an Austrian zoologist, ethologist, and ornithologist. He shared the 1973 Nobel Prize in Physiology or Medicine with Nikolaas Tinbergen and Karl von Frisch. He is often regarded as one of the founders of modern ethology, the study of animal behaviour. He developed an approach that began with an earlier generation, including his teacher Oskar Heinroth.

Lorenz studied instinctive behavior in animals, especially in greylag geese and jackdaws. Working with geese, he investigated the principle of imprinting, the process by which some nidifugous birds (i.e. birds that leave their nest early) bond instinctively with the first moving object that they see within the first hours of hatching. Although Lorenz did not discover the topic, he became widely known for his descriptions of imprinting as an instinctive bond. In 1936 he met Tinbergen, and the two collaborated in developing ethology as a separate sub-discipline of biology. A Review of General Psychology survey, published in 2002, ranked Lorenz as the 65th most cited scholar of the 20th century in the technical psychology journals, introductory psychology textbooks, and survey responses.

Lorenz's work was interrupted by the onset of World War II and in 1941 he was recruited into the German Army as a medic. In 1944 he was sent to the Eastern Front where he was captured by the Soviet Red Army and spent four years as a German prisoner of war. After the war he regretted his membership in the Nazi Party.

Lorenz wrote numerous books, some of which, such as King Solomon's Ring, On Aggression, and Man Meets Dog, became popular reading. His last work "Here I Am – Where Are You?" is a summary of his life's work and focuses on his famous studies of greylag geese.

Biography

Lorenz in 1904 with his older brother

 

In his autobiographical essay, published in 1973 in Les Prix Nobel (winners of the prizes are requested to provide such essays), Lorenz credits his career to his parents, who "were supremely tolerant of my inordinate love for animals", and to his childhood encounter with Selma Lagerlöf's The Wonderful Adventures of Nils, which filled him with a great enthusiasm about wild geese. "

At the request of his father, Adolf Lorenz, he began a premedical curriculum in 1922 at Columbia University, but he returned to Vienna in 1923 to continue his studies at the University of Vienna. He graduated as Doctor of Medicine (MD) in 1928 and became an assistant professor at the Institute of Anatomy until 1935. He finished his zoological studies in 1933 and received his second doctorate (PhD).

While still a student, Lorenz began developing what would become a large menagerie, ranging from domestic to exotic animals. In his popular book King Solomon's Ring, Lorenz recounts that while studying at the University of Vienna he kept a variety of animals at his parents' apartment, ranging from fish to a capuchin monkey named Gloria.

In 1936, at an international scientific symposium on instinct, Lorenz met his great friend and colleague Nikolaas Tinbergen. Together they studied geese—wild, domestic, and hybrid. One result of these studies was that Lorenz "realized that an overpowering increase in the drives of feeding as well as of copulation and a waning of more differentiated social instincts is characteristic of very many domestic animals". Lorenz began to suspect and fear "that analogous processes of deterioration may be at work with civilized humanity." This observation of bird hybrids caused Lorenz to believe that domestication resulting from urbanisation in humans might also cause dysgenic effects, and to argue in two papers that the Nazi eugenics policies against this were therefore scientifically justified.

Lorenz as a Soviet POW in 1944

 

In 1940 he became a professor of psychology at the University of Königsberg. He was drafted into the Wehrmacht in 1941. He sought to be a motorcycle mechanic, but instead he was assigned as a military psychologist, conducting racial studies on humans in occupied Poznań under Rudolf Hippius. The objective was to study the biological characteristics of "German-Polish half-breeds" to determine whether they 'benefitted' from the same work ethics as 'pure' Germans. The degree to which Lorenz participated in the project is unknown, but the project director Hippius referred a couple of times to Lorenz as an "examining psychologist".

Lorenz later described that he once saw transports of concentration camp inmates at Fort VII near Poznań, which made him "fully realize the complete inhumanity of the Nazis".

He was sent to the Russian front in 1944 where he quickly became a prisoner of war in the Soviet Union from 1944 to 1948. In captivity he continued to work as a medic and "got quite friendly with some Russians, mostly doctors". When he was repatriated, he was allowed to keep the manuscript of a book he had been writing, and his pet starling. He arrived back in Altenberg (his family home, near Vienna) both "with manuscript and bird intact." The manuscript became his 1973 book Behind the Mirror.

The Max Planck Society established the Lorenz Institute for Behavioral Physiology in Buldern, Germany, in 1950. In his memoirs Lorenz described the chronology of his war years differently from what historians have been able to document after his death. He himself claimed that he was captured in 1942, where in reality he was only sent to the front and captured in 1944, leaving out entirely his involvement with the Poznań project.

In 1958, Lorenz transferred to the Max Planck Institute for Behavioral Physiology in Seewiesen. He shared the 1973 Nobel Prize in Physiology or Medicine "for discoveries in individual and social behavior patterns" with two other important early ethologists, Nikolaas Tinbergen and Karl von Frisch. In 1969, he became the first recipient of the Prix mondial Cino Del Duca. He was a friend and student of renowned biologist Sir Julian Huxley (grandson of "Darwin's bulldog", Thomas Henry Huxley). Famed psychoanalyst Ralph Greenson and Sir Peter Scott were good friends. Lorenz and Karl Popper were childhood friends; many years after they met, during the celebration of Popper's 80 years, they wrote together a book entitled Die Zukunft ist offen.

He retired from the Max Planck Institute in 1973 but continued to research and publish from Altenberg and Grünau im Almtal in Austria. He died on 27 February 1989 in Altenberg. 

Ethology

Lorenz is recognized as one of the founding fathers of the field of ethology, the study of animal behavior. He is best known for his discovery of the principle of attachment, or imprinting, through which in some species a bond is formed between a new born animal and its caregiver. This principle had been discovered by Douglas Spalding in the 19th century, and Lorenz's mentor Oskar Heinroth had also worked on the topic, but Lorenz's description of Prägung, imprinting, in nidifugous birds such as greylag geese in his 1935 book Der Kumpan in der Umwelt des Vogels ("The Companion in the Environment of Birds") became the foundational description of the phenomenon.

Here, Lorenz used Jakob von Uexküll's concept of Umwelt to understand how the limited perception of animals filtered out certain phenomena with which they interacted instinctively. For example, a young goose instinctively bonds with the first moving stimulus it perceives, whether it be its mother, or a person. Lorenz showed that this behavior of imprinting is what allows the goose to learn to recognize members of its own species, enabling them to be the object of subsequent behavior patterns such as mating. He developed a theory of instinctive behavior that saw behavior patterns as largely innate but triggered through environmental stimuli, for example the hawk/goose effect. He argued that animals have an inner drive to carry out instinctive behaviors, and that if they do not encounter the right stimulus they will eventually engage in the behavior with an inappropriate stimulus.

Lorenz's approach to ethology derived from a skepticism towards the studies of animal behavior done in laboratory settings. He considered that in order to understand the mechanisms of animal behavior, it was necessary to observe their full range of behaviors in their natural context. Lorenz did not carry out much traditional fieldwork but observed animals near his home. His method involved empathizing with animals, often using anthropomorphization to imagine their mental states. He believed that animals were capable of experiencing many of the same emotions as humans.

Tinbergen, Lorenz's friend with whom he conjointly received the Nobel prize, summarized Lorenz's major contribution to ethology as making behavior a topic of biological inquiry, considering behavior a part of an animal's evolutionary equipment. Tinbergen and Lorenz contributed to making Ethology a recognized sub-discipline within Biology and founded the first specialized journal of the field "Ethology" (originally "Zeitschift für Tierpsychologie").

Politics

Lorenz joined the Nazi Party in 1938 and accepted a university chair under the Nazi regime. In his application for party membership he wrote, "I'm able to say that my whole scientific work is devoted to the ideas of the National Socialists." His publications during that time led in later years to allegations that his scientific work had been contaminated by Nazi sympathies. His published writing during the Nazi period included support for Nazi ideas of "racial hygiene" couched in pseudoscientific metaphors.

In his autobiography, Lorenz wrote:

I was frightened—as I still am—by the thought that analogous genetical processes of deterioration may be at work with civilized humanity. Moved by this fear, I did a very ill-advised thing soon after the Germans had invaded Austria: I wrote about the dangers of domestication and, in order to be understood, I couched my writing in the worst of Nazi terminology. I do not want to extenuate this action. I did, indeed, believe that some good might come of the new rulers. The precedent narrow-minded catholic regime in Austria induced better and more intelligent men than I was to cherish this naive hope. Practically all my friends and teachers did so, including my own father who certainly was a kindly and humane man. None of us as much as suspected that the word "selection", when used by these rulers, meant murder. I regret those writings not so much for the undeniable discredit they reflect on my person as for their effect of hampering the future recognition of the dangers of domestication.

After the war, Lorenz denied having been a party member, until his membership application was made public; and he denied having known the extent of the genocide, despite his position as a psychologist in the Office of Racial Policy. He was also shown to have made anti-Semitic jokes on 'Jewish characteristics' in letters to his mentor Heinroth. In 2015 the University of Salzburg posthumously rescinded an honorary doctorate awarded to Lorenz in 1983, citing his party membership and his assertions in his application that he was "always a National Socialist", and that his work "stands to serve National Socialist thought". The university also accused him of using his work to spread "basic elements of the racist ideology of National Socialism".

During the final years of his life, Lorenz supported the fledgling Austrian Green Party and in 1984 became the figurehead of the Konrad Lorenz Volksbegehren, a grass-roots movement that was formed to prevent the building of a power plant at the Danube near Hainburg an der Donau and thus the destruction of the surrounding woodland.

Contributions and legacy

With Nikolaas Tinbergen (left), 1978

 

Lorenz has been called 'The father of ethology', by Niko Tinbergen. Perhaps Lorenz's most important contribution to ethology was his idea that behavior patterns can be studied as anatomical organs. This concept forms the foundation of ethological research. However, Richard Dawkins called Lorenz a "'good of the species' man", stating that the idea of group selection was "so deeply ingrained" in Lorenz's thinking that he "evidently did not realize that his statements contravened orthodox Darwinian theory."

Together with Nikolaas Tinbergen, Lorenz developed the idea of an innate releasing mechanism to explain instinctive behaviors (fixed action patterns). They experimented with "supernormal stimuli" such as giant eggs or dummy bird beaks which they found could release the fixed action patterns more powerfully than the natural objects for which the behaviors were adapted. Influenced by the ideas of William McDougall, Lorenz developed this into a "psychohydraulic" model of the motivation of behavior, which tended towards group selectionist ideas, which were influential in the 1960s. Another of his contributions to ethology is his work on imprinting. His influence on a younger generation of ethologists; and his popular works, were important in bringing ethology to the attention of the general public. 

Lorenz claimed that there was widespread contempt for the descriptive sciences. He attributed this to the denial of perception as the source of all scientific knowledge: "a denial that has been elevated to the status of religion." He wrote that in comparative behavioral research, "it is necessary to describe various patterns of movement, record them, and above all, render them unmistakably recognizable."

There are three research institutions named after Lorenz in Austria: the Konrad Lorenz Institute for Evolution and Cognition Research (KLI) was housed in Lorenz' family mansion at Altenberg before moving to Klosterneuburg in 2013; the Konrad Lorenz Forschungsstelle (KLF) at his former field station in Grünau; and the Konrad Lorenz Institute of Ethology, an external research facility of the University of Veterinary Medicine Vienna.

Vision of the challenges facing humanity

With Nikolaas Tinbergen (right), 1978

 

Lorenz predicted the relationship between market economics and the threat of ecological catastrophe. In his 1973 book, Civilized Man's Eight Deadly Sins, Lorenz addresses the following paradox:

All the advantages that man has gained from his ever-deepening understanding of the natural world that surrounds him, his technological, chemical and medical progress, all of which should seem to alleviate human suffering... tends instead to favor humanity's destruction

Lorenz adopts an ecological model to attempt to grasp the mechanisms behind this contradiction. Thus "all species... are adapted to their environment... including not only inorganic components... but all the other living beings that inhabit the locality." p31.

Fundamental to Lorenz's theory of ecology is the function of negative feedback mechanisms, which, in hierarchical fashion, dampen impulses that occur beneath a certain threshold. The thresholds themselves are the product of the interaction of contrasting mechanisms. Thus pain and pleasure act as checks on each other:

To gain a desired prey, a dog or wolf will do things that, in other contexts, they would shy away from: run through thorn bushes, jump into cold water and expose themselves to risks which would normally frighten them. All these inhibitory mechanisms... act as a counterweight to the effects of learning mechanisms... The organism cannot allow itself to pay a price which is not worth paying. p53.

In nature, these mechanisms tend towards a 'stable state' among the living beings of an ecology:

A closer examination shows that these beings... not only do not damage each other, but often constitute a community of interests. It is obvious that the predator is strongly interested in the survival of that species, animal or vegetable, which constitutes its prey. ... It is not uncommon that the prey species derives specific benefits from its interaction with the predator species... pp31–33.

Lorenz states that humanity is the one species not bound by these mechanisms, being the only one that has defined its own environment:

[The pace of human ecology] is determined by the progress of man's technology (p35)... human ecology (economy) is governed by mechanisms of POSITIVE feedback, defined as a mechanism which tends to encourage behavior rather than to attenuate it (p43). Positive feedback always involves the danger of an 'avalanche' effect... One particular kind of positive feedback occurs when individuals OF THE SAME SPECIES enter into competition among themselves... For many animal species, environmental factors keep... intraspecies selection from [leading to] disaster... But there is no force which exercises this type of healthy regulatory effect on humanity's cultural development; unfortunately for itself, humanity has learned to overcome all those environmental forces which are external to itself p44.

Regarding aggression in human beings, Lorenz states:

Let us imagine that an absolutely unbiased investigator on another planet, perhaps on Mars, is examining human behavior on earth, with the aid of a telescope whose magnification is too small to enable him to discern individuals and follow their separate behavior, but large enough for him to observe occurrences such as migrations of peoples, wars, and similar great historical events. He would never gain the impression that human behavior was dictated by intelligence, still less by responsible morality. If we suppose our extraneous observer to be a being of pure reason, devoid of instincts himself and unaware of the way in which all instincts in general and aggression in particular can miscarry, he would be at a complete loss how to explain history at all. The ever-recurrent phenomena of history do not have reasonable causes. It is a mere commonplace to say that they are caused by what common parlance so aptly terms "human nature." Unreasoning and unreasonable human nature causes two nations to compete, though no economic necessity compels them to do so; it induces two political parties or religions with amazingly similar programs of salvation to fight each other bitterly, and it impels an Alexander or a Napoleon to sacrifice millions of lives in his attempt to unite the world under his scepter. We have been taught to regard some of the persons who have committed these and similar absurdities with respect, even as "great" men, we are wont to yield to the political wisdom of those in charge, and we are all so accustomed to these phenomena that most of us fail to realize how abjectly stupid and undesirable the historical mass behavior of humanity actually is 

Lorenz does not see human independence from natural ecological processes as necessarily bad. Indeed, he states that:

A completely new [ecology] which corresponds in every way to [humanity's] desires... could, theoretically, prove as durable as that which would have existed without his intervention (36).

However, the principle of competition, typical of Western societies, destroys any chance of this:

The competition between human beings destroys with cold and diabolic brutality... Under the pressure of this competitive fury we have not only forgotten what is useful to humanity as a whole, but even that which is good and advantageous to the individual. [...] One asks, which is more damaging to modern humanity: the thirst for money or consuming haste... in either case, fear plays a very important role: the fear of being overtaken by one's competitors, the fear of becoming poor, the fear of making wrong decisions or the fear of not being up to snuff... pp45–47.

In this book, Lorenz proposes that the best hope for mankind lies in our looking for mates based on the kindness of their hearts rather than good looks or wealth. He illustrates this with a Jewish story, explicitly described as such.

Lorenz was one of the early scientists who recognised the significance of human overpopulation. The number one deadly sin of civilized man in his book is overpopulation, which is what leads to aggression. 

Philosophical speculations

In his 1973 book Behind the Mirror: A Search for a Natural History of Human Knowledge, Lorenz considers the old philosophical question of whether our senses correctly inform us about the world as it is, or provide us only with an illusion. His answer comes from evolutionary biology. Only traits that help us survive and reproduce are transmitted. If our senses gave us wrong information about our environment, we would soon be extinct. Therefore, we can be sure that our senses give us correct information, for otherwise we would not be here to be deceived. 

Honours and awards

• Austrian Decoration for Science and Art in 1964
• Elected a Foreign Member of the Royal Society (ForMemRS) in 1964
• Kalinga Prize for the Popularization of Science in 1969
• Gold Medal of the Humboldt Society in 1972
• Nobel Prize in Physiology or Medicine in 1973
• Honorary Doctorate, University of Salzburg, 1983, revoked in 2015
• Grand Cross with Star and Sash of the Order of Merit of the Federal Republic of Germany (Großes Verdienstkreuz mit Stern und Schulterband) in 1984
• Bavarian Maximilian Order for Science and Art in 1984
  

Works

Lorenz's best-known books are King Solomon's Ring and On Aggression, both written for a popular audience. His scientific work appeared mainly in journal articles, written in German; it became widely known to English-speaking scientists through its description in Tinbergen's 1951 book The Study of Instinct, though many of his papers were later published in English translation in the two volumes titled Studies in Animal and Human Behavior.

• King Solomon's Ring (1949) (Er redete mit dem Vieh, den Vögeln und den Fischen, 1949)
• Man Meets Dog (1950) (So kam der Mensch auf den Hund, 1950)
• Evolution and Modification of Behaviour (1965)
• On Aggression (1966) (Das sogenannte Böse. Zur Naturgeschichte der Aggression, 1963)
• Studies in Animal and Human Behavior, Volume I (1970)
• Studies in Animal and Human Behavior, Volume II (1971)
• Motivation of Human and Animal Behavior: An Ethological View. With Paul Leyhausen (1973). New York: D. Van Nostrand Co. ISBN 0-442-24886-5
• Behind the Mirror: A Search for a Natural History of Human Knowledge (1973) (Die Rückseite des Spiegels. Versuch einer Naturgeschichte menschlichen Erkennens, 1973)
• Civilized Man's Eight Deadly Sins (1974) (Die acht Todsünden der zivilisierten Menschheit, 1973)
• The Year of the Greylag Goose (1979) (Das Jahr der Graugans, 1979)
• The Foundations of Ethology (1982)
• The Waning of Humaneness (1987) (Der Abbau des Menschlichen, 1983)
• Here I Am – Where Are You? – A Lifetime's Study of the Uncannily Human Behaviour of the Greylag Goose. (1988). Translated by Robert D. Martin from Hier bin ich – wo bist du?.
• The Natural Science of the Human Species: An Introduction to Comparative Behavioral Research – The Russian Manuscript (1944–1948) (1995)