Navigation

From Wikipedia, the free encyclopedia

Table of geography, hydrography, and navigation, from the 1728 Cyclopaedia

Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.^[1] The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, and space navigation.^[2]

It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks. All navigational techniques involve locating the navigator's position compared to known locations or patterns.

Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and direction.^[2] In this sense, navigation includes orienteering and pedestrian navigation.^[2]

History

In the European medieval period, navigation was considered part of the set of seven mechanical arts, none of which were used for long voyages across open ocean. Polynesian navigation is probably the earliest form of open ocean navigation, it was based on memory and observation recorded on scientific instruments like the Marshall Islands Stick Charts of Ocean Swells. Early Pacific Polynesians used the motion of stars, weather, the position of certain wildlife species, or the size of waves to find the path from one island to another.
Maritime navigation using scientific instruments such as the mariner's astrolabe first occurred in the Mediterranean during the Middle Ages. Although land astrolabes were invented in the Hellenistic period and existed in classical antiquity and the Islamic Golden Age, the oldest record of a sea astrolabe is that of Majorcan astronomer Ramon Llull dating from 1295.^[3] The perfecting of this navigation instrument is attributed to Portuguese navigators during early Portuguese discoveries in the Age of Discovery.^[4][5] The earliest known description of how to make and use a sea astrolabe comes from Spanish cosmographer Martín Cortés de Albacar's Arte de Navegar (The Art of Navigation) published in 1551,^[6] based on the principle of the archipendulum used in constructing the Egyptian pyramids.

Open-seas navigation using the astrolabe and the compass started during the Age of Discovery in the 15th century. The Portuguese began systematically exploring the Atlantic coast of Africa from 1418, under the sponsorship of Prince Henry. In 1488 Bartolomeu Dias reached the Indian Ocean by this route. In 1492 the Spanish monarchs funded Christopher Columbus's expedition to sail west to reach the Indies by crossing the Atlantic, which resulted in the Discovery of America. In 1498, a Portuguese expedition commanded by Vasco da Gama reached India by sailing around Africa, opening up direct trade with Asia. Soon, the Portuguese sailed further eastward, to the Spice Islands in 1512, landing in China one year later.

The first circumnavigation of the earth was completed in 1522 with the Magellan-Elcano expedition, a Spanish voyage of discovery led by Portuguese explorer Ferdinand Magellan and completed by Spanish navigator Juan Sebastián Elcano after the former's death in the Philippines in 1521. The fleet of seven ships sailed from Sanlúcar de Barrameda in Southern Spain in 1519, crossed the Atlantic Ocean and after several stopovers rounded the southern tip of South America. Some ships were lost, but the remaining fleet continued across the Pacific making a number of discoveries including Guam and the Philippines. By then, only two galleons were left from the original seven. The Victoria led by Elcano sailed across the Indian Ocean and north along the coast of Africa, to finally arrive in Spain in 1522, three years after its departure. The Trinidad sailed east from the Philippines, trying to find a maritime path back to the Americas, but was unsuccessful. The eastward route across the Pacific, also known as the tornaviaje (return trip) was only discovered forty years later, when Spanish cosmographer Andrés de Urdaneta sailed from the Philippines, north to parallel 39°, and hit the eastward Kuroshio Current which took its galleon across the Pacific. He arrived in Acapulco on October 8, 1565.

Etymology

The term stems from the 1530s, from Latin navigationem (nom. navigatio), from navigatus, pp. of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" and the root of agere "to drive".^[7]

Basic concepts

Map of Earth
Longitude (λ)
Lines of longitude appear vertical with varying curvature in this projection, but are actually halves of great ellipses, with identical radii at a given latitude.
Latitude (φ)
Lines of latitude appear horizontal with varying curvature in this projection; but are actually circular with different radii. All locations with a given latitude are collectively referred to as a circle of latitude.
The equator divides the planet into a Northern Hemisphere and a Southern Hemisphere, and has a latitude of 0°.

Latitude

Roughly, the latitude of a place on Earth is its angular distance north or south of the equator.^[8] Latitude is usually expressed in degrees (marked with °) ranging from 0° at the Equator to 90° at the North and South poles.^[8] The latitude of the North Pole is 90° N, and the latitude of the South Pole is 90° S.^[8] Mariners calculated latitude in the Northern Hemisphere by sighting the North Star Polaris with a sextant and using sight reduction tables to correct for height of eye and atmospheric refraction. The height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so.

Longitude

Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the prime meridian or Greenwich meridian.^[8] Longitude is usually expressed in degrees (marked with °) ranging from 0° at the Greenwich meridian to 180° east and west. Sydney, for example, has a longitude of about 151° east. New York City has a longitude of 74° west. For most of history, mariners struggled to determine longitude. Longitude can be calculated if the precise time of a sighting is known. Lacking that, one can use a sextant to take a lunar distance (also called the lunar observation, or "lunar" for short) that, with a nautical almanac, can be used to calculate the time at zero longitude (see Greenwich Mean Time).^[9] Reliable marine chronometers were unavailable until the late 18th century and not affordable until the 19th century.^[10][11][12] For about a hundred years, from about 1767 until about 1850,^[13] mariners lacking a chronometer used the method of lunar distances to determine Greenwich time to find their longitude. A mariner with a chronometer could check its reading using a lunar determination of Greenwich time.^[10][14]

Loxodrome

In navigation, a rhumb line (or loxodrome) is a line crossing all meridians of longitude at the same angle, i.e. a path derived from a defined initial bearing. That is, upon taking an initial bearing, one proceeds along the same bearing, without changing the direction as measured relative to true or magnetic north.

Modern technique

Most modern navigation relies primarily on positions determined electronically by receivers collecting information from satellites. Most other modern techniques rely on crossing lines of position or LOP.^[15] A line of position can refer to two different things, either a line on a chart or a line between the observer and an object in real life.^[16] A bearing is a measure of the direction to an object.^[16] If the navigator measures the direction in real life, the angle can then be drawn on a nautical chart and the navigator will be on that line on the chart.^[16]

In addition to bearings, navigators also often measure distances to objects.^[15] On the chart, a distance produces a circle or arc of position.^[15] Circles, arcs, and hyperbolae of positions are often referred to as lines of position.

If the navigator draws two lines of position, and they intersect he must be at that position.^[15] A fix is the intersection of two or more LOPs.^[15]

If only one line of position is available, this may be evaluated against the Dead reckoning position to establish an estimated position.^[17]

Lines (or circles) of position can be derived from a variety of sources:

• celestial observation (a short segment of the circle of equal altitude, but generally represented as a line),
• terrestrial range (natural or man made) when two charted points are observed to be in line with each other,^[18]
• compass bearing to a charted object,
• radar range to a charted object,
• on certain coastlines, a depth sounding from echo sounder or hand lead line.

There are some methods seldom used today such as "dipping a light" to calculate the geographic range from observer to lighthouse.

Methods of navigation have changed through history.^[19] Each new method has enhanced the mariner's ability to complete his voyage.^[19] One of the most important judgments the navigator must make is the best method to use.^[19] Some types of navigation are depicted in the table.

Modern navigation methods

Illustration	Description	Application
	Dead reckoning or DR, in which one advances a prior position using the ship's course and speed. The new position is called a DR position. It is generally accepted that only course and speed determine the DR position. Correcting the DR position for leeway, current effects, and steering error result in an estimated position or EP. An inertial navigator develops an extremely accurate EP.[19]	Used at all times.
	Pilotage involves navigating in restricted waters with frequent determination of position relative to geographic and hydrographic features.[19]	When within sight of land.
	Celestial navigation involves reducing celestial measurements to lines of position using tables, spherical trigonometry, and almanacs.	Used primarily as a backup to satellite and other electronic systems in the open ocean.[19]

Electronic navigation covers any method of position fixing using electronic means, including:
	Radio navigation uses radio waves to determine position by either radio direction finding systems or hyperbolic systems, such as Decca, Omega and LORAN-C.	Losing ground to GPS.
	Radar navigation uses radar to determine the distance from or bearing of objects whose position is known. This process is separate from radar's use as a collision avoidance system.[19]	Primarily when within radar range of land.
	Satellite navigation uses artificial earth satellite systems, such as GPS, to determine position.[19]	Used in all situations.

The practice of navigation usually involves a combination of these different methods.^[19]

Mental navigation checks

By mental navigation checks, a pilot or a navigator estimates tracks, distances, and altitudes which will then help the pilot avoid gross navigation errors.

Piloting

Manual navigation through Dutch airspace

Piloting (also called pilotage) involves navigating an aircraft by visual reference to landmarks,^[20] or a water vessel in restricted waters and fixing its position as precisely as possible at frequent intervals.^[21] More so than in other phases of navigation, proper preparation and attention to detail are important.^[21] Procedures vary from vessel to vessel, and between military, commercial, and private vessels.^[21]

A military navigation team will nearly always consist of several people.^[21] A military navigator might have bearing takers stationed at the gyro repeaters on the bridge wings for taking simultaneous bearings, while the civilian navigator must often take and plot them himself.^[21] While the military navigator will have a bearing book and someone to record entries for each fix, the civilian navigator will simply pilot the bearings on the chart as they are taken and not record them at all.^[21]

If the ship is equipped with an ECDIS, it is reasonable for the navigator to simply monitor the progress of the ship along the chosen track, visually ensuring that the ship is proceeding as desired, checking the compass, sounder and other indicators only occasionally.^[21] If a pilot is aboard, as is often the case in the most restricted of waters, his judgement can generally be relied upon, further easing the workload.^[21] But should the ECDIS fail, the navigator will have to rely on his skill in the manual and time-tested procedures.^[21]

Celestial navigation

A celestial fix will be at the intersection of two or more circles.

Celestial navigation systems are based on observation of the positions of the Sun, Moon, Planets and navigational stars. Such systems are in use as well for terrestrial navigating as for interstellar navigating. By knowing which point on the rotating earth a celestial object is above and measuring its height above the observer's horizon, the navigator can determine his distance from that subpoint. A nautical almanac and a marine chronometer are used to compute the subpoint on earth a celestial body is over, and a sextant is used to measure the body's angular height above the horizon. That height can then be used to compute distance from the subpoint to create a circular line of position. A navigator shoots a number of stars in succession to give a series of overlapping lines of position. Where they intersect is the celestial fix. The moon and sun may also be used. The sun can also be used by itself to shoot a succession of lines of position (best done around local noon) to determine a position.^[22]

Marine chronometer

In order to accurately measure longitude, the precise time of a sextant sighting (down to the second, if possible) must be recorded. Each second of error is equivalent to 15 seconds of longitude error, which at the equator is a position error of .25 of a nautical mile, about the accuracy limit of manual celestial navigation.

The spring-driven marine chronometer is a precision timepiece used aboard ship to provide accurate time for celestial observations.^[22] A chronometer differs from a spring-driven watch principally in that it contains a variable lever device to maintain even pressure on the mainspring, and a special balance designed to compensate for temperature variations.^[22]

A spring-driven chronometer is set approximately to Greenwich mean time (GMT) and is not reset until the instrument is overhauled and cleaned, usually at three-year intervals.^[22] The difference between GMT and chronometer time is carefully determined and applied as a correction to all chronometer readings.^[22] Spring-driven chronometers must be wound at about the same time each day.^[22]

Quartz crystal marine chronometers have replaced spring-driven chronometers aboard many ships because of their greater accuracy.^[22] They are maintained on GMT directly from radio time signals.^[22] This eliminates chronometer error and watch error corrections.^[22] Should the second hand be in error by a readable amount, it can be reset electrically.^[22]

The basic element for time generation is a quartz crystal oscillator.^[22] The quartz crystal is temperature compensated and is hermetically sealed in an evacuated envelope.^[22] A calibrated adjustment capability is provided to adjust for the aging of the crystal.^[22]

The chronometer is designed to operate for a minimum of 1 year on a single set of batteries.^[22] Observations may be timed and ship's clocks set with a comparing watch, which is set to chronometer time and taken to the bridge wing for recording sight times.^[22] In practice, a wrist watch coordinated to the nearest second with the chronometer will be adequate.^[22]

A stop watch, either spring wound or digital, may also be used for celestial observations.^[22] In this case, the watch is started at a known GMT by chronometer, and the elapsed time of each sight added to this to obtain GMT of the sight.^[22]

All chronometers and watches should be checked regularly with a radio time signal.^[22] Times and frequencies of radio time signals are listed in publications such as Radio Navigational Aids.^[22]

The marine sextant

The marine sextant is used to measure the elevation of celestial bodies above the horizon.

The second critical component of celestial navigation is to measure the angle formed at the observer's eye between the celestial body and the sensible horizon. The sextant, an optical instrument, is used to perform this function. The sextant consists of two primary assemblies. The frame is a rigid triangular structure with a pivot at the top and a graduated segment of a circle, referred to as the "arc", at the bottom. The second component is the index arm, which is attached to the pivot at the top of the frame. At the bottom is an endless vernier which clamps into teeth on the bottom of the "arc". The optical system consists of two mirrors and, generally, a low power telescope. One mirror, referred to as the "index mirror" is fixed to the top of the index arm, over the pivot. As the index arm is moved, this mirror rotates, and the graduated scale on the arc indicates the measured angle ("altitude").

The second mirror, referred to as the "horizon glass", is fixed to the front of the frame. One half of the horizon glass is silvered and the other half is clear. Light from the celestial body strikes the index mirror and is reflected to the silvered portion of the horizon glass, then back to the observer's eye through the telescope. The observer manipulates the index arm so the reflected image of the body in the horizon glass is just resting on the visual horizon, seen through the clear side of the horizon glass.

Adjustment of the sextant consists of checking and aligning all the optical elements to eliminate "index correction". Index correction should be checked, using the horizon or more preferably a star, each time the sextant is used. The practice of taking celestial observations from the deck of a rolling ship, often through cloud cover and with a hazy horizon, is by far the most challenging part of celestial navigation.^{[citation needed]}

Inertial navigation

Inertial navigation system is a dead reckoning type of navigation system that computes its position based on motion sensors. Once the initial latitude and longitude is established, the system receives impulses from motion detectors that measure the acceleration along three or more axes enabling it to continually and accurately calculate the current latitude and longitude. Its advantages over other navigation systems are that, once the starting position is set, it does not require outside information, it is not affected by adverse weather conditions and it cannot be detected or jammed. Its disadvantage is that since the current position is calculated solely from previous positions, its errors are cumulative, increasing at a rate roughly proportional to the time since the initial position was input. Inertial navigation systems must therefore be frequently corrected with a location 'fix' from some other type of navigation system. The US Navy developed a Ships Inertial Navigation System (SINS) during the Polaris missile program to ensure a safe, reliable and accurate navigation system for its missile submarines. Inertial navigation systems were in wide use until satellite navigation systems (GPS) became available. Inertial Navigation Systems are still in common use on submarines, since GPS reception or other fix sources are not possible while submerged.

Electronic navigation

Radio navigation

A radio direction finder or RDF is a device for finding the direction to a radio source. Due to radio's ability to travel very long distances "over the horizon", it makes a particularly good navigation system for ships and aircraft that might be flying at a distance from land.
RDFs works by rotating a directional antenna and listening for the direction in which the signal from a known station comes through most strongly. This sort of system was widely used in the 1930s and 1940s. RDF antennas are easy to spot on German World War II aircraft, as loops under the rear section of the fuselage, whereas most US aircraft enclosed the antenna in a small teardrop-shaped fairing.

In navigational applications, RDF signals are provided in the form of radio beacons, the radio version of a lighthouse. The signal is typically a simple AM broadcast of a morse code series of letters, which the RDF can tune in to see if the beacon is "on the air". Most modern detectors can also tune in any commercial radio stations, which is particularly useful due to their high power and location near major cities.

Decca, OMEGA, and LORAN-C are three similar hyperbolic navigation systems. Decca was a hyperbolic low frequency radio navigation system (also known as multilateration) that was first deployed during World War II when the Allied forces needed a system which could be used to achieve accurate landings. As was the case with Loran C, its primary use was for ship navigation in coastal waters. Fishing vessels were major post-war users, but it was also used on aircraft, including a very early (1949) application of moving-map displays. The system was deployed in the North Sea and was used by helicopters operating to oil platforms.

The OMEGA Navigation System was the first truly global radio navigation system for aircraft, operated by the United States in cooperation with six partner nations. OMEGA was developed by the United States Navy for military aviation users. It was approved for development in 1968 and promised a true worldwide oceanic coverage capability with only eight transmitters and the ability to achieve a four-mile (6 km) accuracy when fixing a position. Initially, the system was to be used for navigating nuclear bombers across the North Pole to Russia. Later, it was found useful for submarines.[1] Due to the success of the Global Positioning System the use of Omega declined during the 1990s, to a point where the cost of operating Omega could no longer be justified. Omega was terminated on September 30, 1997 and all stations ceased operation.

LORAN is a terrestrial navigation system using low frequency radio transmitters that use the time interval between radio signals received from three or more stations to determine the position of a ship or aircraft. The current version of LORAN in common use is LORAN-C, which operates in the low frequency portion of the EM spectrum from 90 to 110 kHz. Many nations are users of the system, including the United States, Japan, and several European countries. Russia uses a nearly exact system in the same frequency range, called CHAYKA. LORAN use is in steep decline, with GPS being the primary replacement. However, there are attempts to enhance and re-popularize LORAN. LORAN signals are less susceptible to interference and can penetrate better into foliage and buildings than GPS signals.

Radar navigation

Radar ranges and bearings can be very useful navigation.

When a vessel is within radar range of land or special radar aids to navigation, the navigator can take distances and angular bearings to charted objects and use these to establish arcs of position and lines of position on a chart.^[23] A fix consisting of only radar information is called a radar fix.^[24]

Types of radar fixes include "range and bearing to a single object,"^[25] "two or more bearings,"^[25] "tangent bearings,"^[25] and "two or more ranges."^[25]

Parallel indexing is a technique defined by William Burger in the 1957 book The Radar Observer's Handbook.^[26] This technique involves creating a line on the screen that is parallel to the ship's course, but offset to the left or right by some distance.^[26] This parallel line allows the navigator to maintain a given distance away from hazards.^[26]

Some techniques have been developed for special situations. One, known as the "contour method," involves marking a transparent plastic template on the radar screen and moving it to the chart to fix a position.^[27]

Another special technique, known as the Franklin Continuous Radar Plot Technique, involves drawing the path a radar object should follow on the radar display if the ship stays on its planned course.^[28] During the transit, the navigator can check that the ship is on track by checking that the pip lies on the drawn line.^[28]

Smartphone navigation

In the modern era, smartphones act as personal GPS navigators for any civilian.

Satellite navigation

Global Navigation Satellite System or GNSS is the term for satellite navigation systems that provide positioning with global coverage. A GNSS allow small electronic receivers to determine their location (longitude, latitude, and altitude) to within a few metres using time signals transmitted along a line of sight by radio from satellites. Receivers on the ground with a fixed position can also be used to calculate the precise time as a reference for scientific experiments.

As of October 2011, only the United States NAVSTAR Global Positioning System (GPS) and the Russian GLONASS are fully globally operational GNSSs. The European Union's Galileo positioning system is a next generation GNSS in the initial deployment phase, scheduled to be operational by 2013. China has indicated it may expand its regional Beidou navigation system into a global system.

More than two dozen GPS satellites are in medium Earth orbit, transmitting signals allowing GPS receivers to determine the receiver's location, speed and direction.

Since the first experimental satellite was launched in 1978, GPS has become an indispensable aid to navigation around the world, and an important tool for map-making and land surveying. GPS also provides a precise time reference used in many applications including scientific study of earthquakes, and synchronization of telecommunications networks.

Developed by the United States Department of Defense, GPS is officially named NAVSTAR GPS (NAVigation Satellite Timing And Ranging Global Positioning System). The satellite constellation is managed by the United States Air Force 50th Space Wing. The cost of maintaining the system is approximately US$750 million per year,^[29] including the replacement of aging satellites, and research and development. Despite this fact, GPS is free for civilian use as a public good.

Navigation processes

Ships and similar vessels

Day's work in navigation

The Day's work in navigation is a minimal set of tasks consistent with prudent navigation. The definition will vary on military and civilian vessels, and from ship to ship, but takes a form resembling:^[30]

1. Maintain a continuous dead reckoning plot.
2. Take two or more star observations at morning twilight for a celestial fix (prudent to observe 6 stars).
3. Morning sun observation. Can be taken on or near prime vertical for longitude, or at any time for a line of position.
4. Determine compass error by azimuth observation of the sun.
5. Computation of the interval to noon, watch time of local apparent noon, and constants for meridian or ex-meridian sights.
6. Noontime meridian or ex-meridian observation of the sun for noon latitude line. Running fix or cross with Venus line for noon fix.
7. Noontime determination the day's run and day's set and drift.
8. At least one afternoon sun line, in case the stars are not visible at twilight.
9. Determine compass error by azimuth observation of the sun.
10. Take two or more star observations at evening twilight for a celestial fix (prudent to observe 6 stars).

Passage planning

Poor passage planning and deviation from the plan can lead to groundings, ship damage and cargo loss.

Passage planning or voyage planning is a procedure to develop a complete description of vessel's voyage from start to finish. The plan includes leaving the dock and harbor area, the en route portion of a voyage, approaching the destination, and mooring. According to international law, a vessel's captain is legally responsible for passage planning,^[31] however on larger vessels, the task will be delegated to the ship's navigator.^[32]

Studies show that human error is a factor in 80 percent of navigational accidents and that in many cases the human making the error had access to information that could have prevented the accident.^[32] The practice of voyage planning has evolved from penciling lines on nautical charts to a process of risk management.^[32]

Passage planning consists of four stages: appraisal, planning, execution, and monitoring,^[32] which are specified in International Maritime Organization Resolution A.893(21), Guidelines For Voyage Planning,^[33] and these guidelines are reflected in the local laws of IMO signatory countries (for example, Title 33 of the U.S. Code of Federal Regulations), and a number of professional books or publications. There are some fifty elements of a comprehensive passage plan depending on the size and type of vessel.

The appraisal stage deals with the collection of information relevant to the proposed voyage as well as ascertaining risks and assessing the key features of the voyage. This will involve considering the type of navigation required e.g. Ice navigation, the region the ship will be passing through and the hydrographic information on the route. In the next stage, the written plan is created. The third stage is the execution of the finalised voyage plan, taking into account any special circumstances which may arise such as changes in the weather, which may require the plan to be reviewed or altered. The final stage of passage planning consists of monitoring the vessel's progress in relation to the plan and responding to deviations and unforeseen circumstances.

Land navigation

Navigation for cars and other land-based travel typically uses maps, landmarks, and in recent times computer navigation ("satnav", short for satellite navigation), as well as any means available on water.

Computerized navigation commonly relies on GPS for current location information, a navigational map database of roads and navigable routes, and uses algorithms related to the shortest path problem to identify optimal routes.

Integrated bridge systems

Electronic integrated bridge concepts are driving future navigation system planning.^[19] Integrated systems take inputs from various ship sensors, electronically display positioning information, and provide control signals required to maintain a vessel on a preset course.^[19] The navigator becomes a system manager, choosing system presets, interpreting system output, and monitoring vessel response.^[19]

Evolution of morality

From Wikipedia, the free encyclopedia

The evolution of morality refers to the emergence of human moral behavior over the course of human evolution. Morality can be defined as a system of ideas about right and wrong conduct. In everyday life, morality is typically associated with human behavior, and not much thought is given to the social conducts of other creatures. The emerging fields of evolutionary biology and in particular sociobiology have argued that, though human social behaviors are complex, the precursors of human morality can be traced to the behaviors of many other social animals. Sociobiological explanations of human behavior are still controversial. The traditional view of social scientists has been that morality is a construct, and is thus culturally relative, although others argue that there is a science of morality.

Animal sociality

Though animals may not possess what humans may perceive as moral behavior, all social animals have had to modify or restrain their behaviors for group living to be worthwhile. Typical examples of behavioral modification can be found in the societies of ants, bees and termites. Ant colonies may possess millions of individuals. E. O. Wilson argues that the single most important factor that leads to the success of ant colonies is the existence of a sterile worker caste. This caste of females are subservient to the needs of their mother, the queen, and in so doing, have given up their own reproduction in order to raise brothers and sisters. The existence of sterile castes among these social insects significantly restricts the competition for mating and in the process fosters cooperation within a colony. Cooperation among ants is vital, because a solitary ant has an improbable chance of long-term survival and reproduction. However, as part of a group, colonies can thrive for decades. As a consequence, ants are one of the most successful families of species on the planet, accounting for a biomass that rivals that of the human species.^[1][2]

The basic reason that social animals live in groups is that opportunities for survival and reproduction are much better in groups than living alone. The social behaviors of mammals are more familiar to humans. Highly social mammals such as primates and elephants have been known to exhibit traits that were once thought to be uniquely human, like empathy and altruism.^[3][4]

Primate sociality

Humanity’s closest living relatives are common chimpanzees and bonobos. These primates share a common ancestor with humans who lived four to six million years ago. It is for this reason that chimpanzees and bonobos are viewed as the best available surrogate for this common ancestor. Barbara King argues that while primates may not possess morality in the human sense, they do exhibit some traits that would have been necessary for the evolution of morality. These traits include high intelligence, a capacity for symbolic communication, a sense of social norms, realization of "self", and a concept of continuity.^[5][6][7] Frans de Waal and Barbara King both view human morality as having grown out of primate sociality. Many social animals such as primates, dolphins, and whales have shown to exhibit what Michael Shermer refers to as premoral sentiments. According to Shermer, the following characteristics are shared by humans and other social animals, particularly the great apes:

attachment and bonding, cooperation and mutual aid, sympathy and empathy, direct and indirect reciprocity, altruism and reciprocal altruism, conflict resolution and peacemaking, deception and deception detection, community concern and caring about what others think about you, and awareness of and response to the social rules of the group.^[8]

Shermer argues that these premoral sentiments evolved in primate societies as a method of restraining individual selfishness and building more cooperative groups. For any social species, the benefits of being part of an altruistic group should outweigh the benefits of individualism. For example, lack of group cohesion could make individuals more vulnerable to attack from outsiders. Being part of group may also improve the chances of finding food. This is evident among animals that hunt in packs to take down large or dangerous prey.

Social Evolution of Humans^[9]

Period years ago	Society type	Number of individuals
6,000,000	Bands	10s
100,000–10,000	Bands	10s–100s
10,000–5,000	Tribes	100s–1,000s
5,000–4,000	Chiefdoms	1,000s–10,000s
4,000–3,000	States	10,000s–100,000s
3,000–present	Empires	100,000–1,000,000s

All social animals have hierarchical societies in which each member knows its own place.^{[citation needed]} Social order is maintained by certain rules of expected behavior and dominant group members enforce order through punishment. However, higher order primates also have a sense of reciprocity. Chimpanzees remember who did them favors and who did them wrong.^{[citation needed]} For example, chimpanzees are more likely to share food with individuals who have previously groomed them.^[10] Vampire bats also demonstrate a sense of reciprocity and altruism. They share blood by regurgitation, but do not share randomly. They are most likely to share with other bats who have shared with them in the past or who are in dire need of feeding.^[11]

Animals such as Capuchin monkeys^[12] and dogs^[13] also display an understanding of fairness, refusing to co-operate when presented unequal rewards for the same behaviors.

Chimpanzees live in fission-fusion groups that average 50 individuals. It is likely that early ancestors of humans lived in groups of similar size. Based on the size of extant hunter gatherer societies, recent paleolithic hominids lived in bands of a few hundred individuals. As community size increased over the course of human evolution, greater enforcement to achieve group cohesion would have been required. Morality may have evolved in these bands of 100 to 200 people as a means of social control, conflict resolution and group solidarity. This numerical limit is theorized to be hard coded in our genes since even modern humans have difficulty maintaining stable social relationships with more than 100–200 people. According to Dr. de Waal, human morality has two extra levels of sophistication that are not found in primate societies. Humans enforce their society's moral codes much more rigorously with rewards, punishments and reputation building. People also apply a degree of judgment and reason not seen in the animal kingdom.^{[citation needed]}

The punishment problems

While groups may benefit from avoiding certain behaviors, those harmful behaviors have the same effect regardless of whether the offending individuals are aware of them or not.^[14] Since the individuals themselves can increase their reproductive success by doing many of them, any characteristics that entail impunity are positively selected by evolution.^[15] Specifically punishing individuals aware of their breach of rules would select against the ability to be aware of it, precluding any coevolution of both conscious choice and a sense of it being the basis for moral and penal liability in the same species.^[16]

Human social intelligence

The social brain hypothesis, detailed by R.I.M Dunbar in the article The Social Brain Hypothesis and Its Implications for Social Evolution, supports the fact that the brain originally evolved to process factual information. The brain allows an individual to recognize patterns, perceive speech, develop strategies to circumvent ecologically-based problems such as foraging for food, and also permits the phenomenon of color vision. Furthermore, having a large brain is a reflection of the large cognitive demands of complex social systems. It is said that in humans and primates the neocortex is responsible for reasoning and consciousness. Therefore, in social animals, the neocortex came under intense selection to increase in size to improve social cognitive abilities. Social animals, such as humans are capable of two important concepts, coalition formation, or group living, and tactical deception, which is a tactic of presenting false information to others. The fundamental importance of animal social skills lies within the ability to manage relationships and in turn, the ability to not just commit information to memory, but manipulate it as well.^[17] An adaptive response to the challenges of social interaction and living is theory of mind. Theory of mind as defined by M. Brune, is the ability to infer another individual's mental states or emotions.^[18] Having a strong theory of mind is tied closely with possessing advanced social intelligence. Collectively, group living requires cooperation and generates conflict. Social living puts strong evolutionary selection pressures on acquiring social intelligence due to the fact that living in groups has advantages. Advantages to group living include protection from predators and the fact that groups in general outperform the sum of an individual’s performance. But, from an objective point of view, group living also has disadvantages, such as, competition from within the group for resources and mates. This sets the stage for something of an evolutionary arms race from within the species.

Within populations of social animals, altruism, or acts of behavior that are disadvantageous to one individual while benefiting other group members has evolved. This notion seems to be contradictory to evolutionary thought, due to the fact that an organism's fitness and success is defined by its ability to pass genes on to the next generation. According to E. Fehr, in the article, The Nature of Human Altruism, the evolution of altruism can be accounted for when kin selection and inclusive fitness are taken into account; meaning reproductive success is not just dependent on the number of offspring an individual produces, but also the number of offspring that related individuals produce.^[19] Outside of familial relationships altruism is also seen, but in a different manner typically defined by the prisoner's dilemma, theorized by John Nash. The prisoner's dilemma serves to define cooperation and defecting with and against individuals driven by incentive, or in Nash's proposed case, years in jail. In evolutionary terms, the best strategy to use for the prisoner's dilemma is tit-for-tat. In the tit-for-tat strategy, an individual should cooperate as long others are cooperating, and not defect until another individual defects against them. At their core, complex social interactions are driven by the need to distinguish sincere cooperation and defection.

Brune details that theory of mind has been traced back to primates, but it is not observed to the extent that it is in the modern human. The emergence of this unique trait is perhaps where the divergence of the modern human begins, along with our acquisition of language. Humans use metaphors and imply much of what we say. Phrases such as, "You know what I mean?" are not uncommon and are direct results of the sophistication of the human theory of mind. Failure to understand another's intentions and emotions can yield inappropriate social responses and are often associated with human mental conditions such as autism, schizophrenia, bipolar disorder, some forms of dementia, and psychopathy. This is especially true for autism spectrum disorders, where social disconnect is evident, but non-social intelligence can be preserved or even in some cases augmented, such as in the case of a savant.^[18] The need for social intelligence surrounding theory of mind is a possible answer to the question as to why morality has evolved as a part of human behavior.

Evolution of religion

Psychologist Matt J. Rossano muses that religion emerged after morality and built upon morality by expanding the social scrutiny of individual behavior to include supernatural agents. By including ever watchful ancestors, spirits and gods in the social realm, humans discovered an effective strategy for restraining selfishness and building more cooperative groups.^[20] The adaptive value of religion would have enhanced group survival.^[21][22]

The Wason selection task

In an experiment where subjects must demonstrate abstract, complex reasoning, researchers have found that humans (as has been seen in other animals) have a strong innate ability to reason about social exchanges. This ability is believed to be intuitive, since the logical rules do not seem to be accessible to the individuals for use in situations without moral overtones.^[23]

Emotion

Disgust, one of the basic emotions, may have an important role in certain forms of morality. Disgust is argued to be a specific response to certain things or behaviors that are dangerous or undesirable from an evolutionary perspective. One example is things that increase the risk of an infectious disease such as spoiled foods, dead bodies, other forms of microbiological decomposition, a physical appearance suggesting sickness or poor hygiene, and various body fluids such as feces, vomit, phlegm, and blood. Another example is disgust against evolutionary disadvantageous mating such as incest (the incest taboo) or unwanted sexual advances.^[4] Still another example are behaviors that may threaten group cohesion or cooperation such as cheating, lying, and stealing. MRI studies have found that such situations activate areas in the brain associated with disgust.^[24]

Evolutionary psychology of religion

From Wikipedia, the free encyclopedia

The evolutionary psychology of religion is the study of religious belief using evolutionary psychology principles. It is one approach to the psychology of religion. As with all other organs and organ functions, the brain's functional structure is argued to have a genetic basis, and is therefore subject to the effects of natural selection and evolution. Evolutionary psychologists seek to understand cognitive processes, religion in this case, by understanding the survival and reproductive functions they might serve.^[1]

Mechanisms of evolution

There is general agreement among scientists that a propensity to engage in religious behavior evolved early in human history. However, there is disagreement on the exact mechanisms that drove the evolution of the religious mind. There are two schools of thought. One is that religion itself evolved due to natural selection and is an adaptation, in which case religion conferred some sort of evolutionary advantage. The other is that religious beliefs and behaviors may have emerged as by-products of other adaptive traits without initially being selected for because of their own benefits.^[2][3][4]

Religious behavior often involves significant costs including economic costs, celibacy, dangerous rituals, or by spending time that could be used otherwise. This would suggest that natural selection should act against religious behavior unless it or something else causing religious behavior to have significant advantages.^[5]

Religion as an adaptation

Richard Sosis and Candace Alcorta have reviewed several of the prominent theories for the adaptive value of religion.^[2] Many are "social solidarity theories", which view religion as having evolved to enhance cooperation and cohesion within groups. Group membership in turn provides benefits which can enhance an individual's chances for survival and reproduction. These benefits range from coordination advantages^[4] to the facilitation of costly behavior rules.^[3]

These social solidarity theories may help to explain the painful or dangerous nature of many religious rituals. Costly-signaling theory suggests that such rituals might serve as public and hard-to-fake signals that an individual's commitment to the group is sincere. Since there would be a considerable benefit in trying to cheat the system - taking advantage of group living benefits without taking on any possible costs - the ritual would not be something simple that can be taken lightly.^[2] Warfare is a good example of a cost of group living, and Richard Sosis, Howard C. Kress, and James S. Boster carried out a cross-cultural survey which demonstrated that men in societies which engage in war do submit to the costliest rituals.^[6]

Studies that show more direct positive associations between religious practice and health and longevity are more controversial. Harold G. Koenig and Harvey J. Cohen summarized and assessed the results of 100 evidence-based studies that systematically examined the relationship between religion and human well-being, finding that 79% showed a positive influence.^[7] These studies are popular in the media, as seen in a recent NPR program including University of Miami Professor Gail Ironson's findings that belief in God and a strong sense of spirituality were good predictors of a lower viral load and improved immune cell levels in HIV patients.^[8] However, Dr. Richard P. Sloan of Columbia University was quoted in the New York Times as saying that "...there is no really good compelling evidence that there is a relationship between religious involvement and health."^[9] There is still debate over the validity of these findings, and they do not necessarily prove a direct cause-and-effect relationship between religion and health. Mark Stibich claims there is a clear correlation but the reason for it is unclear.^[10] A criticism of such placebo effects, as well as the advantage of religion giving a sense of meaning, is that it seems likely that less complex mechanisms than religious behavior could achieve such goals.^[5]

Religion as a by-product

Stephen Jay Gould cites religion as an example of an exaptation or spandrel, but he does not himself select a definite trait which he thinks was actually acted on by natural selection. He does, however, bring up Freud's suggestion that our large brains, which evolved for other reasons, led to consciousness. The beginning of consciousness forced humans to deal with the concept of personal mortality. Religion may have been one solution to this problem.^[11]

Other researchers have proposed specific psychological processes which may have been co-opted for religion. Such mechanisms may include the ability to infer the presence of organisms that might do harm (agent detection), the ability to come up with causal narratives for natural events (etiology), and the ability to recognize that other people have minds of their own with their own beliefs, desires and intentions (theory of mind). These three adaptations (among others) allow human beings to imagine purposeful agents behind many observations that could not readily be explained otherwise, e.g. thunder, lightning, movement of planets, complexity of life.^[12]

Pascal Boyer suggests, in his book Religion Explained, that there is no simple explanation for religious consciousness. He builds on the ideas of cognitive anthropologists Dan Sperber and Scott Atran, who argued that religious cognition represents a by-product of various evolutionary adaptations, including folk psychology. He argues that one such factor is that it has, in most cases, been advantageous for humans to remember "minimally counter-intuitive" concepts which are somewhat different from the daily routine and somewhat violate innate expectations about how the world is constructed. A god that is in many aspects like humans but much more powerful is such a concept, while the often much more abstract god discussed at length by theologians is often too counter-intuitive. Experiments support that religious people think about their god in anthropomorphic terms even if this contradicts the more complex theological doctrines of their religion.^[5]

Pierre Lienard and Pascal Boyer suggest that humans have evolved a "hazard-precaution system" which allows us to detect potential threats in the environment and attempt to respond appropriately.^[13] Several features of ritual behaviors, often a major feature of religion, are held to trigger this system. These include the occasion for the ritual, often the prevention or elimination of danger or evil, the harm believed to result from nonperformance of the ritual, and the detailed proscriptions for proper performance of the ritual. Lienard and Boyer discuss the possibility that a sensitive hazard-precaution system itself may have provided fitness benefits, and that religion then "associates individual, unmanageable anxieties with coordinated action with others and thereby makes them more tolerable or meaningful".

Justin L. Barrett in Why Would Anyone Believe in God? suggests that belief in God is natural because it depends on mental tools possessed by all human beings. He suggests that the way our minds are structured and develop make belief in the existence of a supreme god with properties such as being superknowing, superpowerful and immortal highly attractive. He also compares belief in God to belief in other minds, and devotes a chapter to looking at the evolutionary psychology of atheism. He suggests that one of the fundamental mental modules in the brain is the Hyperactive Agency Detection Device (HADD), another potential system for identifying danger. This HADD may confer a survival benefit even if it is over-sensitive: it is better to avoid an imaginary predator than be killed by a real one. This would tend to encourage belief in ghosts and spirits.^[14]

Though hominids probably began using their emerging cognitive abilities to meet basic needs like nutrition and mates, Terror Management Theory argues that this happened before they had reached the point where significant self (and thus end-of-self) awareness arose. Death awareness became a highly disruptive byproduct of prior adaptive functions. The resulting anxiety threatened to undermine these very functions and thus needed amelioration. Any social formation or practice that was to be widely accepted by the masses needed to provide a means of managing this terror. The main strategy to do so was to "become an individual of value in a world of meaning…acquiring self-esteem [via] the creation and maintenance of culture", as this would counter the sense of insignificance represented by death and provide 1) symbolic immortality through the legacy of a culture that lives on beyond the physical self ("earthly significance") 2) literal immortality, the promise of an afterlife or continued existence featured in religions ("cosmic significance").^[15]

Memes

Richard Dawkins suggests in The Selfish Gene that cultural memes function like genes in that they are subject to natural selection. In The God Delusion Dawkins further argues that because religious truths cannot be questioned, their very nature encourages religions to spread like "mind viruses". In such a conception, it is necessary that the individuals who are unable to question their beliefs are more biologically fit than individuals who are capable of questioning their beliefs. Thus, it could be concluded that sacred scriptures or oral traditions created a behavioral pattern that elevated biological fitness for believing individuals. Individuals who were capable of challenging such beliefs, even if the beliefs were enormously improbable, became rarer and rarer in the population.

This model holds that religion is the byproduct of the cognitive modules in the human brain that arose in our evolutionary past to deal with problems of survival and reproduction. Initial concepts of supernatural agents may arise in the tendency of humans to "overdetect" the presence of other humans or predators (momentarily mistaking a vine for a snake). For instance, a man might report that he felt something sneaking up on him, but it vanished when he looked around.^[16]

Stories of these experiences are especially likely to be retold, passed on and embellished due to their descriptions of standard ontological categories (person, artifact, animal, plant, natural object) with counterintuitive properties (humans that are invisible, houses that remember what happened in them, etc.). These stories become even more salient when they are accompanied by activation of non-violated expectations for the ontological category (houses that "remember" activates our intuitive psychology of mind; i.e. we automatically attribute thought processes to them).^[17]

One of the attributes of our intuitive psychology of mind is that humans are interested in the affairs of other humans. This may result in the tendency for concepts of supernatural agents to inevitably cross connect with human intuitive moral feelings (evolutionary behavioral guidelines). In addition, the presence of dead bodies creates an uncomfortable cognitive state in which dreams and other mental modules (person identification and behavior prediction) continue to run decoupled from reality producing incompatible intuitions that the dead are somehow still around. When this is coupled with the human predisposition to see misfortune as a social event (as someone's responsibility rather than the outcome of mechanical processes) it may activate the intuitive "willingness to make exchanges" module of the human theory of minds resulting in the tendency of humans to try to interact and bargain with their supernatural agents (ritual).^[18]

In a large enough group, some individuals will seem better skilled at these rituals than others and will become specialists. As the societies grow and encounter others, competition will ensue and a "survival of the fittest" effect may cause the practitioners to modify their concepts to provide a more abstract, more widely acceptable version. Eventually the specialist practitioners form a cohesive group or guild with its attendant political goals (religion).^[18]