Evolution of morality

In evolutionary psychology, 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 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 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 species on the planet, accounting for a biomass that rivals humans.

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.

Primate sociality
Humanity’s closest living relatives are common chimpanzees and bonobos. These primates are known to 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. 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.

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.

All social animals have hierarchical societies in which each member knows its own place. 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. For example, chimpanzees are more likely to share food with individuals who have previously groomed them. 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 have shared with them in the past, and who are in dire need of feeding as bats who haven't fed in three days risk death from starvation.

Animals such as Capuchin monkeys and dogs 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.

Evolution of religion
Psychologist Matt J. Rossano argues 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. The adaptive value of religion would have enhanced group survival.

Sexuality and morality
Human sexuality is intricately linked with notions of virtue and modesty. In particular, compared to males, females tend to be under more intense social scrutiny regarding promiscuous behavior. Evolutionary psychology suggests that this differential application of sexual morality may be an evolutionary adaptation related to parental investment. Because women invest more resources into rearing children, such as a nine month gestation, it is argued that they must select a mate who is willing to participate in rearing children. Consequently, women have evolved more exacting criteria for mates than men. Women have a stronger preference for long term partners, whereas men have preferences for both long and short term partners. The theory supposes that men are more open to dropping their standards for short term partners as there is no parental investment. In this regard, promiscuous behavior by women would be maladaptive, as they would have to raise children with no or little parental support. In most societies, female adultery is generally seen as a greater moral infraction than is male adultery.

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.

Disgust
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. 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.