Despite wide acceptance that the attributes of living creatures have appeared through a cumulative evolutionary process guided chiefly by natural selection, many human activities have seemed analytically inaccessible through such an approach. Prominent evolutionary biologists, for example, have described morality as contrary to the direction of biological evolution, and moral philosophers rarely regard evolution as relevant to their discussions. -/- The Biology of Moral Systems adopts the position that moral questions arise out of conflicts of interest, and that moral systems (...) are ways of using confluences of interest at lower levels of social organiation to deal with conflicts of interest at higher levels. Moral systems are described as systems of indirect reciprocity: humans gain and lose socially and reproductively not only by direct transactions, but also by the reputations they gain from the everyday flow of social interactions. -/- The author develops a general theory of human interests, using senescence and effort theory from biology, to help analye the patterning of human lifetimes. He argues that the ultimate interests of humans are reproductive, and that the concept of morality has arisen within groups because of its contribution to unity in the context, ultimately, of success in intergroup competition. He contends that morality is not easily relatable to universals, and he carries this argument into a discussion of what he calls the greatest of all moral problems, the nuclear arms race. (shrink)

A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate -against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds: and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can (...) be explained by the model. Specifically, friendship,d islike, 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, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance appropriate to the local social and ecological environment. (shrink)

In this book, I make use of an idea from economics to suggest how noble human tendencies might not only have survived the ruthless pressures of the material world, but actually have been nurtured by them.

Several attempts have recently been made to explain moral systems and moral sentiments in light of evolutionary biological theory. It may be helpful to modify and extend this project with the help of a theory of communication developed by ethologists. The core of this approach is the idea that signals are best seen as attempts to manipulate others rather than as attempts to inform them. This addition helps to clarify some problematic areas in the evolutionary study of morals, and it (...) generates new, testable predictions about moral statements. (shrink)

An important contribution to medical anthropology, this work defines the principal causes if illness that are reported throughout the world, distinguishing those involving natural causation from the more widely prevalent hypotheses advancing supernatural explanations.

Robert Boyd*†, Herbert Gintis‡, Samuel Bowles§, and Peter J. Richerson¶.

Human cooperation is held to be an evolutionary puzzle because people voluntarily engage in costly cooperation, and costly punishment of non-cooperators, even among anonymous strangers they will never meet again. The costs of such cooperation cannot be recovered through kin-selection, reciprocal altruism, indirect reciprocity, or costly signaling. A number of recent authors label this behavior ‘strong reciprocity’, and argue that it is: (a) a newly documented aspect of human nature, (b) adaptive, and (c) evolved by group selection. We argue exactly (...) the opposite; that the phenomenon is: (a) not new, (b) maladaptive, and (c) evolved by individual selection. In our perspective, the apparent puzzle disappears to reveal a biological and evolutionary logic to human cooperation. Group selection may play a role in theory, but it is neither necessary nor sufficient to explain human cooperation. Our alternative solution is simpler, makes fewer assumptions, and is more parsimonious with the empirical data. (shrink)

Having a criminal justice system that imposes sanctions no doubt does deter criminal conduct. But available social science research suggests that manipulating criminal law rules within that system to achieve heightened deterrence effects generally will be ineffective. Potential offenders often do not know of the legal rules. Even if they do, they frequently are unable to bring this knowledge to bear in guiding their conduct, due to a variety of situational, social, or chemical factors. Even if they can, a rational (...) analysis commonly puts the perceived benefits of crime greater than its perceived costs, due to a variety of criminal justice realities such as low punishment rates. These conclusions are reinforced by studies of crime rates following rule changes. Many show no change in deterrent effect. Those that purport to show a deterrent effect commonly have persuasive non-deterrence explanations, such as a change in incapacitative effect. The few studies that segregate deterrent and incapacitative effects tend to reinforce the conclusion that rule formulation has a deterrent effect only in those unusual situations in which the preconditions to deterrence exist. Even there, the deterrent effects are quite minor and unpredictable, hence inadequate grounds to influence criminal law rule making. (shrink)

Across religious belief systems, some supernatural agents are nearly always granted privileged epistemic access into the self's thoughts. In addition, the ethnographic literature supports the claim that, across cultures, supernatural agents are envisioned as incapable of being deceived through overt behaviors; preoccupied with behavior in the moral domain; punitive agents who cause general misfortune to those who transgress and; committed to an implicit social contract with believers that is dependent on the rules of reciprocal altruism. The present article examines the (...) possibility that these factors comprise a developmentally based, adaptive information-processing system that increased the net genetic fitness of ancestral human beings living within complex social groups. In particular, the authors argue that fear of supernatural punishment, whether in this life or in the hereafter, encouraged the inhibition of selfish actions that were associated with "real" punishment by actual group members. (shrink)

Emotion is normally regulated in the human brain by a complex circuit consisting of the orbital frontal cortex, amygdala, anterior cingulate cortex, and several other interconnected regions. There are both genetic and environmental contributions to the structure and function of this circuitry. We posit that impulsive aggression and violence arise as a consequence of faulty emotion regulation. Indeed, the prefrontal cortex receives a major serotonergic projection, which is dysfunctional in individuals who show impulsive violence. Individuals vulnerable to faulty regulation of (...) negative emotion are at risk for violence and aggression. Research on the neural circuitry of emotion regulation suggests new avenues of intervention for such at-risk populations. (shrink)

In this paper I explore the psychology of ritual performance and present a simple graphical model that clarifies several issues in William Irons’s theory of religion as a “hard-to-fake” sign of commitment. Irons posits that religious behaviors or rituals serve as costly signals of an individual’s commitment to a religious group. Increased commitment among members of a religious group may facilitate intra-group cooperation, which is argued to be the primary adaptive benefit of religion. Here I propose a proximate explanation for (...) how individuals are able to pay the short-term costs of ritual performance to achieve the long-term fitness benefits offered by religious groups. The model addresses three significant problems raised by Irons’s theory. First, the model explains why potential free-riders do not join religious groups even when there are significant net benefits that members of religious groups can achieve. Second, the model clarifies how costly a ritual must be to achieve stability and prevent potential free-riders from joining the religious group. Third, the model suggests why religious groups may require adherents to perform private rituals that are not observed by others. Several hypotheses generated from the model are also discussed. (shrink)

We investigated whether (a) people positively reevaluate the characters of recently dead others and (b) supernatural primes concerning an ambient dead agent serve to curb selfish intentions. In Study 1, participants made trait attributions to three strangers depicted in photographs; one week later, they returned to do the same but were informed that one of the strangers had died over the weekend. Participants rated the decedent target more favorably after learning of his death whereas ratings for the control targets remained (...) unchanged between sessions. This effect was especially pronounced for traits dealing with the decedent’s prosocial tendencies (e.g., ethical, kind). In Study 2, a content analysis of obituaries revealed a similar emphasis on decedents’ prosocial attributes over other personality dimensions (e.g., achievement-relatedness, social skills). Finally, in Study 3, participants who were told of an alleged ghost in the laboratory were less likely to cheat on a competitive task than those who did not receive this supernatural prime. The findings are interpreted as evidence suggestive of adaptive design. (shrink)