Evolution of morality

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The concept of 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 rather than animal behavior. The emerging fields of evolutionary biology, and in particular evolutionary psychology, have argued that, despite the complexity of human social behaviors, the precursors of human morality can be traced to the behaviors of many other social animals. Sociobiological explanations of human behavior remain controversial. Social scientists have traditionally viewed morality as a construct, and thus as culturally relative, although others such as Sam Harris argue that there is an objective science of morality.

Contents

Animal sociality

Though other 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] 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. [7]

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 a 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 [8]
Period years ago Society typeNumber of individuals
6,000,000Bands10s
100,000–10,000Bands10s–100s
10,000–5,000Tribes100s–1,000s
5,000–4,000Chiefdoms1,000s–10,000s
4,000–3,000States10,000s–100,000s
3,000–presentEmpires100,000–1,000,000s

All social animals have 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. [9] 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. [10]

Animals such as Capuchin monkeys [11] and dogs [12] 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 other 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 ]

Adaptive valley of disgust at cruel individual altruism

Some evolutionary biologists and game theorists argue that since gradual evolutionary models of morality require incremental evolution of altruism in populations where egoism and cruelty initially reigned, any sense of occasional altruism from otherwise egoistic and cruel individuals being worse than consistent cruelty would have made evolution of morality impossible due to early stages of moral evolution being selected against by such sentiments causing the individuals with some morality to be treated worse than those with no morality. This would have caused low degree morality to become an adaptive valley that would preclude the early steps away from the no morality condition, precluding an early necessary condition for later evolution of higher degrees of morality. These scientists argue that while this rules out evolutionary explanations of the specific type of morality that feels disgust at some empathy from rarely empathic individuals by assuming it to be psychopathic Machiavellianism, it does not rule out evolution of other types of morality that accept a little altruism as better than no altruism at all. [13] [14]

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. [15] Since the individuals themselves can increase their reproductive success by doing many of them, any characteristics that entail impunity are positively selected by evolution. [16] 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. [17]

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. [18] An adaptive response to the challenges of social interaction and living is theory of mind. Theory of mind as defined by Martin Brüne, is the ability to infer another individual's mental states or emotions. [19] 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. [20] 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. [19] 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 third-party 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. [21] The adaptive value of religion would have enhanced group survival. [22] [23]

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. [24]

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. [25]

See also

Related Research Articles

<span class="mw-page-title-main">Altruism</span> Principle or practice of concern for the welfare of others

Altruism is the principle and practice of concern for the well-being and/or happiness of other humans or animals above oneself. While objects of altruistic concern vary, it is an important moral value in many cultures and religions. It may be considered a synonym of selflessness, the opposite of selfishness.

Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evolved to solve. In this framework, psychological traits and mechanisms are either functional products of natural and sexual selection or non-adaptive by-products of other adaptive traits.

Sociobiology is a field of biology that aims to explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within the study of human societies, sociobiology is closely allied to evolutionary anthropology, human behavioral ecology, evolutionary psychology, and sociology.

<span class="mw-page-title-main">Morality</span> Differentiation between right and wrong

Morality is the differentiation of intentions, decisions and actions between those that are distinguished as proper (right) and those that are improper (wrong). Morality can be a body of standards or principles derived from a code of conduct from a particular philosophy, religion or culture, or it can derive from a standard that a person believes should be universal. Morality may also be specifically synonymous with "goodness" or "rightness".

<span class="mw-page-title-main">Frans de Waal</span> Dutch primatologist and ethologist (1948–2024)

Franciscus Bernardus Maria "Frans" de Waal was a Dutch primatologist and ethologist. He was the Charles Howard Candler Professor of Primate Behavior in the Department of Psychology at Emory University in Atlanta, Georgia, director of the Living Links Center at the Yerkes National Primate Research Center at Emory, and author of numerous books including Chimpanzee Politics (1982) and Our Inner Ape (2005). His research centered on primate social behavior, including conflict resolution, cooperation, inequity aversion, and food-sharing. He was a member of the United States National Academy of Sciences and the Royal Netherlands Academy of Arts and Sciences.

<span class="mw-page-title-main">Group selection</span> Proposed mechanism of evolution

Group selection is a proposed mechanism of evolution in which natural selection acts at the level of the group, instead of at the level of the individual or gene.

In biology, altruism refers to behaviour by an individual that increases the fitness of another individual while decreasing their own. Altruism in this sense is different from the philosophical concept of altruism, in which an action would only be called "altruistic" if it was done with the conscious intention of helping another. In the behavioural sense, there is no such requirement. As such, it is not evaluated in moral terms—it is the consequences of an action for reproductive fitness that determine whether the action is considered altruistic, not the intentions, if any, with which the action is performed.

The evolution of human intelligence is closely tied to the evolution of the human brain and to the origin of language. The timeline of human evolution spans approximately seven million years, from the separation of the genus Pan until the emergence of behavioral modernity by 50,000 years ago. The first three million years of this timeline concern Sahelanthropus, the following two million concern Australopithecus and the final two million span the history of the genus Homo in the Paleolithic era.

Evolutionary ethics is a field of inquiry that explores how evolutionary theory might bear on our understanding of ethics or morality. The range of issues investigated by evolutionary ethics is quite broad. Supporters of evolutionary ethics have claimed that it has important implications in the fields of descriptive ethics, normative ethics, and metaethics.

Cognitive specialization suggests that certain behaviors, often in the domain of social communication, are passed on to offspring and refined to be maximally beneficial by the process of natural selection. Specializations serve an adaptive purpose for an organism by allowing the organism to be better suited for its habitat. Over time, specializations often become essential to the species' continued survival. Cognitive specialization in humans has been thought to underlie the acquisition, development, and evolution of language, theory of mind, and specific social skills such as trust and reciprocity. These specializations are considered to be critical to the survival of the species, even though there are successful individuals who lack certain specializations, including those diagnosed with autism spectrum disorder or who lack language abilities. Cognitive specialization is also believed to underlie adaptive behaviors such as self-awareness, navigation, and problem solving skills in several animal species such as chimpanzees and bottlenose dolphins.

<span class="mw-page-title-main">Jean Decety</span> American neuroscientist

Jean Decety is an American–French neuroscientist specializing in developmental neuroscience, affective neuroscience, and social neuroscience. His research focuses on the psychological and neurobiological mechanisms underpinning social cognition, particularly social decision-making, empathy, moral reasoning, altruism, pro-social behavior, and more generally interpersonal relationships. He is Irving B. Harris Distinguished Service Professor at the University of Chicago.

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.

<span class="mw-page-title-main">Evolutionary origin of religion</span> Emergence of religious behavior discussed in terms of natural evolution

The evolutionary origin of religion and religious behavior is a field of study related to evolutionary psychology, the origin of language and mythology, and cross-cultural comparison of the anthropology of religion. Some subjects of interest include Neolithic religion, evidence for spirituality or cultic behavior in the Upper Paleolithic, and similarities in great ape behavior.

Natural morality refers to morality that is based on human nature, rather than acquired from societal norms or religious teachings. Charles Darwin's theory of evolution is central to many modern conceptions of natural morality, but the concept goes back at least to naturalism.

Veneer theory is a term coined by Dutch primatologist Frans de Waal to label the Hobbesian view of human morality that he criticizes throughout his work. Although he criticizes this view in earlier works, the term in this form is introduced in his 2005 book Our Inner Ape, denoting a concept that he rejects, namely that human morality is "a cultural overlay, a thin veneer hiding an otherwise selfish and brutish nature". The idea of the veneer theory goes back to Thomas Henry Huxley and has more recently been advocated by biologists like George C. Williams.

<span class="mw-page-title-main">Disgust</span> Basic emotion

Disgust is an emotional response of rejection or revulsion to something potentially contagious or something considered offensive, distasteful or unpleasant. In The Expression of the Emotions in Man and Animals, Charles Darwin wrote that disgust is a sensation that refers to something revolting. Disgust is experienced primarily in relation to the sense of taste, and secondarily to anything which causes a similar feeling by sense of smell, touch, or vision. Musically sensitive people may even be disgusted by the cacophony of inharmonious sounds. Research has continually proven a relationship between disgust and anxiety disorders such as arachnophobia, blood-injection-injury type phobias, and contamination fear related obsessive–compulsive disorder.

The history of evolutionary psychology began with Charles Darwin, who said that humans have social instincts that evolved by natural selection. Darwin's work inspired later psychologists such as William James and Sigmund Freud but for most of the 20th century psychologists focused more on behaviorism and proximate explanations for human behavior. E. O. Wilson's landmark 1975 book, Sociobiology, synthesized recent theoretical advances in evolutionary theory to explain social behavior in animals, including humans. Jerome Barkow, Leda Cosmides and John Tooby popularized the term "evolutionary psychology" in their 1992 book The Adapted Mind: Evolutionary Psychology and The Generation of Culture. Like sociobiology before it, evolutionary psychology has been embroiled in controversy, but evolutionary psychologists see their field as gaining increased acceptance overall.

Evolutionary biologists have developed various theoretical models to explain the evolution of food-sharing behavior—"[d]efined as the unresisted transfer of food" from one food-motivated individual to another—among humans and other animals.

Reciprocal altruism in humans refers to an individual behavior that gives benefit conditionally upon receiving a returned benefit, which draws on the economic concept – ″gains in trade″. Human reciprocal altruism would include the following behaviors : helping patients, the wounded, and the others when they are in crisis; sharing food, implement, knowledge.

Parochial altruism is a concept in social psychology, evolutionary biology, and anthropology that describes altruism towards an in-group, often accompanied by hostility towards an out-group. It is a combination of altruism, defined as behavior done for the benefit of others without direct effect on the self, and parochialism, which refers to having a limited viewpoint. Together, these concepts create parochial altruism, or altruism which is limited in scope to one's in-group. Parochial altruism is closely related to the concepts of in-group favoritism and out-group discrimination. Research has suggested that parochial altruism may have evolved in humans to promote high levels of in-group cooperation, which is advantageous for group survival. Parochial altruism is often evoked to explain social behaviors within and between groups, such as why people are cooperative within their social groups and why they may be aggressive towards other social groups.

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Further reading