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Biocultural Evolution of Human Altruistic Behavior

This article deals with the evolution of altruistic behavior in humans. As a couple of arguments show, humans possess an evolved altruistic behavior. The evolution of altruism is, thus, argued to have genetic dimensions, social dimensions, and psychological dimensions. Human altruism has evolved through differing processes and developed different types and identifying characteristic features. The genetic or biological aspects of the arguments of the evolution of human altruistic behavior emphasize on the gene level effect of altruism that includes altruistic behaviors in some animals such as chimpanzees. The social aspects of the arguments emphasize on the group control, that is, punishment of noncooperators and rewarding of collaborators. This might have led to the moral development of human kind. The cognitive aspects of the arguments have genetic link, on one hand, and moral dimensions, on the other hand. This article generally focuses on concepts related to the evolution of human altruism such as group selection, cooperative selection, kin-selection, and various associated characteristics.

What is Human Altruism?

Altruism is defined as a behavior costly to the actor and beneficial to the recipient, which is measured in lifetime personal fitness consequences. Human altruism occurs in two opposite ways in which, on the one hand, a minority of altruists can force a majority of selfish individuals to cooperate or a few egoists can induce a large number of altruists to defect. Altruists and recipients are environmentally determined, by position in groups or environmental situations; and altruism is therefore a net-gain lottery. Altruism in humans is greatly modified, either reinforced or cancelled, by individual likes and dislikes. Human altruism is responsive not only to kin-related but also to non kin-related ones.> However, some biologists suggest that evolution by selection has produced altruistic behaviors in humans precisely adapted to degrees of kinship, the costs and profits of kin and non-kin altruism, and the profits of selfish cheating and the counter-profits of detecting and preventing it. This seems that altruism has evolved in humans based on genetic relatedness.

In human populations’ altruism, there is cheating or acceptance of altruism without reciprocation. That is, there are nonaltruists in which an increment of their load would lead to elimination of populations. There is also forced altruism in human populations that may evolve into reciprocal altruism. Darlington defines altruism that it is a group phenomenon in which some genes or individuals, which must be presumed to be selfish, benefit others at cost to themselves.

Characteristics of Human Altruism

There are some types of altruism based on the nature and specific characteristics of altruistic behaviors. Clavien and Chapuisat outline that there are four distinct but related concepts of altruism such as psychological altruism, the genuine motivation to improve others' interests and welfare; reproductive altruism, which involves increasing others’ chances of survival and reproduction at the actor’s expense; behavioural altruism, which involves bearing some cost in the interest of others; and finally preference altruism, which is a preference for others' interests. Darlington, on his part, generally, gives an account of the characteristics of altruism. He puts the characteristics of all altruism is potentially reciprocal; potentially profitable to altruists as well as to recipients; environmentally determined, usually by position of individuals in group or environmental situations; and a net-gain lottery Altruism is opposed by competition; costly, complex, and slow, and tending to produce an imprecise flexible altruism rather than a precisely detailed one; and supplemented by group selection (differential extinction of groups). This is a working hypothesis for human altruism as it conforms to these generalizations. Humans altruism is not based on calculation, it is instead, behaved by them altruistically because they possess human altruistic emotions. The human altruism extends far beyond reciprocal altruism and reputation-based cooperation, taking the form of strong reciprocity which is a combination of altruistic rewarding, which is a predisposition to reward others for cooperative, norm-abiding behaviours, and altruistic punishment, which is a propensity to impose sanctions on others for norm violations.

The Evolution of Human Altruism

As Darlington argues, there are no specific genes for altruism that have been found in humans. Human altruism is potentially reciprocal and profitable in which individuals seek profit that exceed the costs. Even though altruism is a group phenomenon, it evolves by individual selection, by processes equivalent to co-evolution. As altruism is a group phenomenon, the groups vary, compete, and undergo selection. These behaviors are naturally selected through different principles of selection of groups and sets: '1) Selection-In-Principle:' a differential elimination of preformed sets, or of sets that have formed themselves by action of their members which is applicable to selection among individual organisms (sets of genes), and groups (sets) of individuals. 2) Darwinian Natural Selection: a differential elimination of individual organisms, or as set selection at the level of living individuals (sets of genes). 3) Group Selection: a differential elimination of preformed groups of individual organisms, or of groups that have formed themselves by action of the individuals concerned. Kitcher describes the ways altruism evolved in human kind. He asks two major inquiries: 1. How do tendencies to kindly, even self-sacrificial, behavior evolve in an unkind, Darwinian world? 2. More exactly, conceiving altruistic behavior, as biologists do, as behavior that promotes the fitness of another organism at costs in fitness to the agent, how can propensities to engage in such behavior originate and be maintained under natural selection? And he suggests two problems needed to be solved: that we must not only explain how altruistic tendencies are sustained once they are prevalent but also how they spread when they are rare.

Contrary to the above arguments, however, Richard Dawkins argues reciprocal altruism as it is the effect of our gene of which is "selfish exploitation.” He argues, if animals live together in groups their genes must get more benefit out of the association than they put in. In this case, the selfish-herd model in itself has no place for cooperative interactions. There is no altruism here, only selfish exploitation by each individual of every other individual. However, he argues, in real life, there are cases where individuals seem to take active steps to preserve fellow members of the group from predators. For example, bird alarm calls that would risk the caller’s identity, though, arguably, it may endanger itself even more by not calling. He generalizes that associations of mutual benefit will evolve if each partner can get more out than he puts in. He argues that cheaters will always do better than suckers. For this effect, man has developed a long memory and a capacity for individual recognition. This implies to Dawkins to expect reciprocal altruism to have played an important part in human evolution. As a result, he argues, many of our psychological characteristics such as envy, guilt, gratitude, sympathy and so forth have been shaped by natural selection for improved ability to cheat, to detect cheats, and to avoid being thought to be a cheat.

Evolution from the Selfish Gene to Altruistic Individual

The idea of altruism is determined by the selfishness of genes. A gene may make the individual carrying it selfish because any consistent sacrifice of a gene without a return would cause an elimination of itself from the gene pool. How then humans maintain their altruistic behavior? Darlington suggests that the presence of an exception that the altruistic genes “might be maintained in gene pools by recurrent mutation; or “pleiotropic genes with altruistic effects slightly disadvantageous to the altruists but combined with other, greater advantageous effects might be maintained by selection; or, under very limited conditions, altruistic genes might be established by deme-group selection” (Darlington 1977:386).

In the selfishness of a gene, Richard Dawkins argues that a single gene tries to get more numerous in the gene pool by helping to program the bodies in which it finds itself to survive and to reproduce. And that gene might 'recognize' copies of itself in other individuals. Therefore, as Dawkins argues, altruism can be identified at the gene level. He claims that the possessor of an altruistic gene might be recognized simply by the fact that he does altruistic acts. This means it is the gene that effects or initiates the altruistic act of the individual. Because of this parents have, he argues, more altruism towards their young as close relatives have greater chance of sharing genes. In this regard, if an individual dies in order to save ten close relatives, one copy of the kin-altruism gene may be lost, but a larger number of copies of the same gene is saved. This is termed as kin selection that accounts for within-family altruism; the closer the relationship, the stronger the selection. As Dawkins argues, genetically speaking, parental care and brother/sister altruism evolve for exactly the same reason: in both cases, there is a good chance that the altruistic gene is present in the body of the beneficiary. In this token, an individual can be expected to invest or risk a certain proportion of his own assets in the life of another individual. He provides a supportive argument that not only humans but also an adult male baboons have been reported to risk their lives defending the rest of the troop against predators for the sake of shared genes among the troops. He argues that a parent cares for his identical twin twice as much as he cares for his children.

Evolution of Cooperative Altruism

Cooperation is defined as the voluntary acting together of two or more individuals that brings about, or could potentially bring about, an end situation that benefits one, both, or all of them in a way that could not have been brought about individually. By employing observational and experimental techniques, Sarah et al distinguished three types of reciprocity. One is of symmetry-based reciprocity which is cognitively the least complex form, based on symmetries inherent in dyadic relationships such as in mutual association and kinship. The second is attitudinal reciprocity, cognitively more complex, is based on the “mirroring” of social attitudes between partners; it is exhibited by both capuchin monkeys and chimpanzees. The third is a calculated reciprocity of which is the most cognitively advanced form; it is based on mental scorekeeping and is found only in humans and possibly chimpanzees.

Human cooperation is a unique feature in the animal world in which they cooperate with genetically unrelated strangers, with people they will never meet again, and when reputation gains are small or absent. Strong reciprocity, the behavioral propensity for altruistic punishment and altruistic rewarding, is of key importance for human cooperation. They claim that evolution has endowed humans with proximate mechanisms that render altruistic behavior psychologically rewarding. Economic experiments show strong reciprocity in cooperation and the enforcement of norm abiding behavior in social dilemma situations is important. Recent research in neuroeconomics reveals the neural basis of human cooperation and strong reciprocity. Capturing cooperation in the laboratory Economists study the essence of the strategic situations underlying cooperation in the ‘prisoners’ dilemma game’ (PD). In the PD, two players simultaneously choose between cooperation and defection. If both decide to cooperate, they both earn a high outcome; if both defect, they both receive a low outcome; and, if one player cooperates and the other defects, the cooperator obtains a very low outcome, whereas the defector receives a very high outcome. Hence, it is always better for a player to defect for any given strategy of the opponent. The PD resembles a generic cooperation dilemma in which purely selfish behavior leads to the defection of both players, even though mutual cooperation would maximize their joint payoff. Cooperation, however, is vulnerable to exploitation. The PD reflects the cooperation dilemma inherent in the provision of a public good, such as cooperative hunting or group defense, with only two individuals involved.

People punish noncooperators not only in long term but also in short term interactions. Existing models suggest that altruistic cooperation among nonrelatives is evolutionarily stable only in small groups. Applying such models to the evolution of altruistic punishment leads to the prediction that people will not incur costs to punish others to provide benefits to large groups of nonrelatives. Altruistic cooperation and altruistic punishment allows altruistic punishment to evolve in populations engaged in one-time, anonymous interactions. This process allows both altruistic punishment and altruistic cooperation to be maintained even when groups are large and other parameter values approximate conditions that characterize cultural evolution in the small-scale societies in which humans lived for most of our prehistory. In the absence of punishment, within-group adaptation acts to decrease altruistic cooperation frequency, and as a result weak drift-like forces are insufficient to maintain substantial variation between groups. Whereas in groups in which altruistic punishers are common, defectors are excluded, and this maintains variation in the amount of cooperation between groups. In such groups punishers bear few costs, and decrease only very slowly in competition with contributors. As a consequence, group selection is more effective at maintaining altruistic punishment than altruistic cooperation. Group selection plays an important role in the cultural evolution of cooperative behavior and moralistic punishment in humans. The importance of group selection is always a quantitative issue. Selection among groups acts to favor individually costly, group beneficial behaviors.

Human reciprocal altruism of friendship, dislike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies that were selected to set the tendencies at a balance appropriate to the local social and ecological environments. “One human being leaping into water, at some danger to himself, to save another distantly related human from drowning may be said to display altruistic behavior. If he were to leap in to save his own child, the behavior would not necessarily be an instance of "altruism"; he may merely be contributing to the survival of his own genes invested in the child” (Trivers 1991:35). Trivers presents three possibilities of altruistic reciprocity: (1) the altruists dispense their altruism randomly throughout the population; (2) they dispense it nonrandomly by regarding their degree of genetic relationship with possible recipients; or (3) they dispense it nonrandomly by regarding the altruistic tendencies of possible recipient.

Possibilities of Altruistic Behavior Selection

There are a set of biological parameters affecting the possibility that reciprocally altruistic behavior will be selected for. (1) Length of lifetime—long lifetime of individuals of a species maximizes the chance that any two individuals will encounter many altruistic situations, and all other things being equal one should search for instances of reciprocal altruism in long-lived species. (2) Dispersal rate—low dispersal rate during all or a significant portion of the lifetime of individuals of a species increases the chance that an individual will interact repeatedly with the same set of neighbors, and other things being equal one should search for instances of reciprocal altruism in such species. (3) Degree of mutual dependence—interdependence of members of a species (to avoid predators, for example) will tend to keep individuals near each other and thus increase the chance they will encounter altruistic situations together. (4) Parental care—a special instance of mutual dependencies that found between parents and offspring in species that show parental care. (5) Dominance hierarchy—linear dominance hierarchies consist of asymmetrical relationships; a given individual is dominant over another but not vice versa. Strong dominance hierarchies reduce the extent to which altruistic situations occur in which the less dominant individual is capable of performing a benefit for the more dominant. (6) Aid in combat—no matter how dominance-oriented a species is, a dominant individual can usually be aided in aggressive encounters with other individuals by help from a less dominant individual.

Reconciliation of selfishness of genes and individuals in reciprocal altruism happens when two or more individuals (or other entities) benefit each other regardless of kinship, each profiting more than its altruism costs. In contrast to kin altruism, that is clearly visible only in exceptional cases, reciprocal altruism is ubiquitous in the real world. “It occurs or may occur between "copies" of the same gene, between different genes in a gene pool, between genetically similar and between genetically different individuals in a population, and between individuals of different species.” As per the prosocial behavioral evolution “strong reciprocity is a predisposition to cooperate with others and to punish those who violate the norms of cooperation, at personal cost, even when it is implausible to expect that these costs will be repaid. Gintisa et al present evidence supporting strong reciprocity as a schema for predicting and understanding altruism in humans; they show that under conditions plausibly characteristic of the early stages of human evolution, a small number of strong reciprocators could invade a population of selfregarding types, and strong reciprocity is an evolutionary stable strategy” (Gintisa, Bowlesa, Boyd, Fehr 2003:153). Cooperation can evolve because only the two players involved in the PD benefit from mutual cooperation.

Forms of Cooperative Altruism

Reputation-seeking: when third parties reward individuals with a good reputation in that people help unrelated others with whom they have no further future interactions because by helping they increase the probability that they themselves receive help in the future. Altruists with green beards: when individuals who reward and punish altruistically have observable characteristics (“green beards”) that distinguish them from non-altruists.” It is in the self-interest of any individual to cooperate with a green beard because noncooperation will be punished. Altruistic punishment evolves because the punishers directly benefit from their observable willingness to punish. “If an altruist meets a selfish individual without a green beard he defects, if he meets a green beard he cooperates. In this way, the benefits of altruistic behaviour are only reaped by the altruists themselves so that universal cooperation evolves” (Fehr & Fischbacher 2005:36). Kin Altruism: Kin or kin-group selection is a form of group selection that does reconcile the presumption of selfishness with the fact of altruism in which individuals make altruistic sacrifices to their kin, paying costs as individuals, but profiting genetically. Gene-Culture co-evolution: sociobiological concept of group selection can at best be relevant in small isolated groups because migration in combination with within-group selection against altruists is a much stronger force than selection between groups. The migration of defectors to groups with a comparatively large number of altruists plus defectors’ within group fitness advantage quickly removes the genetic differences between groups so that group selection has little effect on the overall selection of altruistic traits. In this instance, humans are an intensely social species, frequently performing costly behaviors that benefit others. Helping relatives: humans make energy expenditures and costly sacrifices for their infants and relatedness will increase cooperation and decrease conflict. Beyond Parents and Offspring: though humans generally aid relatives rather than strangers and closer relatives rather than more distant ones, they also help none relatives. “If organisms interact repeatedly over time, and the benefits of receiving cooperation are greater than the cost of performing it, then helping can be favored if individuals preferentially cooperate with those that have aided them previously” (Kurzban, et al 2015:581).

There are four propositions forwarded for reciprocal altruism (though cannot be proved but tested). 1. Altruism is always actually or potentially reciprocal; altruists always receive or "expect" (are statistically likely to receive) direct or indirect returns. 2. Altruism is always actually or potentially profitable to all individuals concerned; all individuals at the beginning of their existence (when the eggs are fertilized or even before) "expect" to gain more than they lose, although the expected profits of different individuals need not be equal. 3. Altruists and recipients are always environmentally, not genetically, differentiated, usually by position in kin groups or environmental situations. 4. Altruism is a net-gain lottery, in which all individuals pay or risk paying costs, but receive or "expect" profits that exceed the costs. These propositions are apparently true of all cases in which altruism is initiated by the altruists, and is evolving or stabilized by selection.

When Does Altruistic Behavior Begin?

Researchers suggest that socially observed altruistic behavior is not a source by itself. Altruistic behavior instead tended to be originated from genetic predispositions. For example, Warneken & Tomasello claim human infants at the ages of 14 to 18 months “help others attain their goals” without expectation of “reward,” “reciprocation” or “reputation” from adults suggesting “that human infants are naturally altruistic”. Before or mainly during the Pleistocene a hominid species would have met the preconditions for the evolution of reciprocal altruism. They include long lifespan; low dispersal rate; life in small, mutually dependent, stable, social groups; and a long period of parental care.

While humans are generally helpful to each other including non-genetically related ones, adult reciprocity is of cultural, which is a product of socialization for “praise” and other social rewards. But young children are naturally altruistic. Human infants and chimpanzees are able to and willing to help others. As per the ontogenetic roots of altruism, children naturally tend to develop altruistic behaviors. Although socialization practices can build upon this predisposition for altruism, it is not its original source. Socialization practices do not operate independently of any altruistic predisposition or even impose altruism on children who are originally purely selfish. They present three lines of evidence: first, altruistic tendencies emerge early in ontogeny before socialization could play a major impact on the development of infants; second, socialization practices in early and middle childhood are only effective if they mesh with this predisposition; and third, nonhuman primates display altruistic tendencies in the absence of any socialization practices.

Cognitive Roots of Altruism

As Dawkins argues, altruism in humans is supposed to have evolved over time.This argument is related with cognitive aspects of mind such as development of memory that helped retrieve information about cheaters and suckers. Studies on instrumental helping, as explained in the following section, indicate the cognitive roots of human altruism.

Ontogenetic roots of instrumental helping

Ontogenetic roots of helping others has a cognitive and emotional dimensions. Warneken & Tomasello claim that instrumental helping consists of both cognitive and a motivational components in order to help someone achieve a goal, one must first recognize what that goal is. This implies the change of state in the environment the actor wishes to bring about. Motivationally, to help an actor achieve a goal, one must be motivated by the sight of his or her achieving his or her goal, or perhaps the sight of his or her pleasure upon achievement. They suggest four types of prosocial behaviors: 1) comforting of which is provision of emotional support to others; 2) sharing of food or objects to others; 3) informing useful information for others; and 4) instrumental helping of which is acting on behalf of the goal of others. They also state that “young children have an intrinsic motivation to act altruistically” that “the ontogenetic roots of altruism are apparent early in childhood” in which infants display spontaneous, unrewarded helping when another person is unable to achieve his goal.

Phylogenetic roots of instrumental helping

There is a cognitive evidence that chimpanzees instrumentally help other’s achieve their goals. They also “appear to have a basic motivation to act altruistically for others. Thus, the phylogenetic roots of human altruism – at least in the form of instrumental helping – may reach as far back as to the last common ancestor of humans and chimpanzees some six million years ago. This argument, therefore, places much weight on the biological origin of human altruism than the social one.

List of Human Altruistic Behaviors

There are some list of types of human altruistic behaviors. They are (1) helping in times of danger (e.g. accidents, predation, intraspecific aggression; (2) sharing food; (3) helping the sick, the wounded, or the very young and old; (4) sharing implements; and (5) sharing knowledge. These behavioral characteristics often meet the criterion of small cost to the giver and great benefit to the taker. All these require one to incur costs.

References

Category:Altruism Category:Human evolution