Mr. Darcy spoke with affectionate praise of his sister's proficiency.I never spoke to you without rather wishing to give you pain than not.Pride and Prejudice has been read in many ways. I argue that this well-known love story not only foregrounds the battle of the sexes but also places center stage the pros and cons of different types of family systems and reciprocal altruism. Humans have long evolved to become homo familiaris. In its Latin origin, the word family does (...) not necessarily refer to blood relations or kinship. Rather, the ancient Romans used familia to refer to "household property—the fields, house, money and slaves owned by a man. The Latin word famulus means 'servant.'"2In Family and Friends in... (shrink)

Atran & Norenzayan (A&N) fail to address several problems with commitment theory as it relates to non-kin altruism in religious contexts. They (1) provide little support for the contention that religious sacrifices function as signals, (2) do not distinguish between religious specialists and lay believers, and (3) conflate definitions of cooperation and sacrifice.

Building on a model first proposed by Gary Johnson, it is hypothesized that religious institutions demanding celibacy and other forms of altruism from members take advantage of human predispositions to favor genetic relatives in order to maintain and reinforce these desired behaviors in non-kin settings. This is accomplished through the institutionalization of practices to manipulate cues through which such relatives are regularly identified. These cues are association, phenotypic similarity, and the use of kin terms. In addition, the age of (...) recruits and their contact with actual kin are factors that relate to kinship recognition and that are similarly manipulated by institutions in order to reinforce altruistic behavior directed toward non-kin. Support for this set of predictions is presented from historical and ethnographic sources on monastic life in Buddhism, Christianity, and Hinduism, as well as Islamic dervish groups, the Essenes, Shakers, and others. Potential implications of the model for understanding the development of religious institutions are preliminarily explored by reviewing Joachim Wach's model of religious developmental stages as well as some of the literature on the relationship between individualism and communalism in incipient religious organizations, in light of the kin-cue manipulation model. (shrink)

Phenomena like meat sharing in hunter-gatherers, altruistic self-sacrifice in intergroup conflicts, and contribution to the production of public goods in laboratory experiments have led to the development of numerous theories trying to explain human prosocial preferences and behavior. Many of these focus on direct and indirect reciprocity, assortment, or (cultural) group selection. Here, I investigate analytically how genetic relatedness changes the incentive structure of that paradigmatic game which is conventionally used to model and experimentally investigate collective action problems: the public (...) goods game. Using data on contemporary hunter-gatherer societies I then estimate a threshold value determining when biological altruism turns into maximizing inclusive fitness in this game. I find that, on average, contributing no less than about 40% of individual fitness to public goods production still is an optimal strategy from an inclusive fitness perspective under plausible socio-ecological conditions. (shrink)

Kin selection and group selection were once seen as competing explanatory hypotheses but now tend to be seen as equivalent ways of describing the same basic idea. Yet this ‘equivalence thesis’ seems not to have brought proponents of kin selection and group selection any closer together. This may be because the equivalence thesis merely shows the equivalence of two statistical formalisms without saying anything about causality. W.D. Hamilton was the first to derive an equivalence result of this type. Yet Hamilton (...) was aware of its limitations, and saw that, while illuminating, it papered over some biologically important distinctions. Attending to these distinctions leads to the concept of ‘K-G space’, which helps us see where the biological disagreements between proponents of kin selection and group selection really lie. (shrink)

Altruism is a malleable notion that is understood differently in various disciplines. The common denominator of most definitions of altruism is the idea of unidirectional helping behaviour. However, a closer examination reveals that the term altruism sometimes refers to the outcomes of a helping behaviour for the agent and its neighbours – i.e. reproductive altruism – and sometimes to what motivates the agent to help others – i.e. psychological altruism. Since these perspectives on altruism (...) are crucially different, it is important to use a clear terminology to avoid confusion. In particular, we show that the notion of altruism used by biologists profoundly differs from the ones used by philosophers, psychologists and economists in cross-disciplinary debates about human altruism. (shrink)

We demonstrate the existence of altruism via kin selection in artificial life and explore its nuances. We do so in the Avida system through a setup that is based on the behavior of colicinogenic bacteria: Organisms can kill unrelated organisms in a given radius but must kill themselves to do so. Initially, we confirm!results found in the bacterial world: Digital organisms do sacrifice themselves for their kin—an extreme example of altruism— and do so more often in structured environments, (...) where kin are always nearby, than in well-mixed environments, where the location of kin is stochastically determined. Having shown that helping one’s kin is advantageous, we turn our attention to investigating the efficacy and implications of the strategies of kincheaters, those who receive help from kin but do not return it. Contrary to the expectations of current theory, we find that kin-cheaters outcompete kin-altruists. Our results cause us to question the stability of strategies that involve altruism between kin. Knowing that kin-altruism persists in biological systems, however, we search for, and find, conditions that allow!kin-based altruism to persist in evolving!systems despite the!presence of kin-cheaters. (shrink)

Humans are often altruistic in a variety of contexts, even toward strangers they may never meet again. What explains this behavior? Many argue that kin selection cannot explain it but group selecti...

According to kin selection theory, indirect reproductive advantages may induce individuals to care for others with whom they share genes by common descent, and the amount of care, including self-sacrifice, will increase with the proportion of genes shared. Twins represent a natural situation in which this hypothesis can be tested. Twin pairs experience the same early environment because they were born and raised at the same time and in the same family but their genetic relatedness differs depending on zygosity. We (...) compared the degree of willingness to fight and sacrifice for the co-twin among monozygotic and dizygotic pairs in a sample of 1443 same-sex and opposite-sex twins. We also analyzed the effect of the subject’s gender and that of the co-twin on those altruistic behaviors. Results partly supported the postulated explanation. MZ twins were significantly more likely than DZ twins to self-sacrifice for their co-twins, but zygosity did not affect willingness to fight for him/her. The genders of the subject and of the co-twin, not genetic relatedness, were the best predictors of aggressive altruistic intentions. (shrink)

According to kin selection theory, indirect reproductive advantages may induce individuals to care for others with whom they share genes by common descent, and the amount of care, including self-sacrifice, will increase with the proportion of genes shared. Twins represent a natural situation in which this hypothesis can be tested. Twin pairs experience the same early environment because they were born and raised at the same time and in the same family but their genetic relatedness differs depending on zygosity. We (...) compared the degree of willingness to fight and sacrifice for the co-twin among monozygotic and dizygotic pairs in a sample of 1443 same-sex and opposite-sex twins. We also analyzed the effect of the subject’s gender and that of the co-twin on those altruistic behaviors. Results partly supported the postulated explanation. MZ twins were significantly more likely than DZ twins to self-sacrifice for their co-twins, but zygosity did not affect willingness to fight for him/her. The genders of the subject and of the co-twin, not genetic relatedness, were the best predictors of aggressive altruistic intentions. (shrink)

Why and under what conditions are individuals altruistic to family and friends in their social networks? Evolutionary psychology suggests that such behaviour is primarily the product of adaptations for kin- and reciprocal altruism, dependent on the degree of genetic relatedness and exchange of benefits, respectively. For this reason, individuals are expected to be more altruistic to family members than to friends: whereas family members can be the recipients of kin and reciprocal altruism, friends can be the recipients of (...) reciprocal altruism only. However, there is a question about how the effect of kinship is implemented at the proximate psychological level. One possibility is that kinship contributes to some general measure of relationship quality (such as ‘emotional closeness’), which in turn explains altruism. Another possibility is that the effect of kinship is independent of relationship quality. The present study tests between these two possibilities. Participants (N= 111) completed a self-report questionnaire about their willingness to be altruistic, and their emotional closeness, to 12 family members and friends at different positions in their extended social networks. As expected, altruism was greater for family than friends, and greater for more central layers of the network. Crucially, the results showed that kinship made a significant unique contribution to altruism, even when controlling for the effects of emotional closeness. Thus, participants were more altruistic towards kin than would be expected if altruism was dependent on emotional closeness alone – a phenomenon we label a ‘kinship premium’. These results have implications for the ongoing debate about the extent to which kin relations and friendships are distinct kinds of social relationships, and how to measure the ‘strength of ties’ in social networks. (shrink)

Kin selection, reciprocity and group selection are widely regarded as evolutionary mechanisms capable of sustaining altruism among humans andother cooperative species. Our research indicates, however, that these mechanisms are only particular examples of a broader set of evolutionary possibilities.In this paper we present the results of a series of simple replicator simulations, run on variations of the 2–player prisoner's dilemma, designed to illustrate the wide range of scenarios under which altruism proves to be robust under evolutionary pressures. The (...) set of mechanisms we explore is divided into four categories :correlation, group selection, imitation, and punishment. We argue that correlation is the core phenomenon at work in all four categories. (shrink)

In recent years, much has been learned about the strategic and organizational contexts of suicide attacks. However, motivations of the agents who commit them remain difficult to explain. In part this is because standard models of social learning as well as Durkheimian notions of sacrificial behavior are inadequate in the face of the actions of human bombers. In addition, the importance of organizational structures and practices in reinforcing commitment on the part of suicide recruits is an under-explored factor in many (...) analyses. This essay examines the potential applicability of evolutionary models of altruism to the understanding of commitment to suicide on the part of terrorist organizational recruits. Three evolutionary models of sacrificial behavior in nonhuman species and many categories of human behavior are explored cross-organizationally: reciprocity, inclusive fitness theory, and induced altruism. Reciprocal altruism is unlikely to be a major motivator in suicide attacks because the costs exhibited by attackers are too high to be adequately compensated. However, the role of evolved self-deception in perceptions of personal death, and thus of rewards in the afterlife, is potentially illuminating. Inclusive fitness theory can help explain the motivations of attackers because rewards to kin often are offered by organizations to suicide recruits. However, suicide bombers also often act out of revenge for the loss of or injury to relatives, and inclusive fitness theory generally, as well as more specific theoretical models of retaliatory aggression, may not adequately account for the bombers' actions. Predictions from induced altruism theory appear to be well supported because suicide terror organizations tend to be tightly structured around practices intended to maintain and reinforce commitment though the manipulation of kinship-recognition cues. (shrink)

A simple and general criterion is derived for the evolution of altruism when individuals interact in pairs. It is argued that the treatment of this problem in kin selection theory and in game theory are special cases of this general criterion.

In attacking utilitarianism Bernard Williams1 likes to consider the case of the man who has a choice of saving his wife or a stranger from drowning. Williams takes it as clear, and a problem for consequentialism, that the man has a moral obligation to save his wife. The relationship is a good thing without reference to consequences that one might suppose it requires if it is to be valuable.David Messick suggests a consequentialist view of certain relationships—for example, those that create (...) a limited altruism—that have survival value. Some kin relationships are like that; and insofar as they are, there is something to be said for them from a utilitarian point of view. Messick does not rest there, as his primary concern is fairness, but he does seem to hold that there is a utilitarian basis for valuing families and family ties. One need not be a sociobiologist to learn something about practical morality from the facts Messick adduces. (shrink)

After a brief discussion of altruism, supererogation, and the duty to rescue in American and Jewish Law, this paper turns to an examination of the challenge to altruism presented by the developing field of evolutionary psychology. Evolutionary psychology is the investigation of animal behavior from the perspective of natural selection. The fundamental issue, as E.O. Wilson says, is the question, "How can altruism, which by definition reduces personal fitness, possibly evolve by natural selection?" According to a seminal (...) article in the field, "Models that attempt to explain altruistic behavior in terms of natural selection are models designed to take the altruism out of altruism." The challenge of evolutionary psychology is that it provides a "genealogy of morals" that many have found to be disturbing. From the evolutionary perspective what crucially matters is the reproductive success of the individual animal, the transmission of its genes to later generations, and this provides the measure of its individual fitness. The evolutionary psychologist's argument proceeds by the introduction of three basic concepts: kin selection , reciprocal altruism, and indirect reciprocity. Each of these concepts is critically analyzed. It is concluded that the current status of altruism and cooperation is not affected by evolutionary history. They do have a genetic basis, but then so does everything about human beings, nastiness as well as cooperation; it does not follow that motives for cooperation are always self-serving. Nach einer kurzen Erörterung von Altruismus, Supererogation und der Hilfeleistungspflicht im amerikanischen und jüdischen Recht wendet sich der Artikel einer Untersuchung der Anforderungen zu, die die Evolutionspsychologie an den Altruismus stellt. Evolutionspsychologie ist die Erforschung tierischen Verhaltens aus der Perspektive der natürlichen Auslese. Das grundlegende Problem ist, wie E.O. Wilson sagt, die Frage: "Wie kann sich Altruismus, der per definitionem die eigenen Fähigkeiten vermindert, durch natürliche Auslese entwickeln?" Nach einem bahnbrechenden Artikel sind "Modelle, die versuchen, altruistisches Verhalten in Begriffen der natürlichen Auslese zu erklären, darauf angelegt, dem Altruismus das Altruistische zu nehmen". Die Herausforderung der Evolutionspsychologie ist die von ihr bereitgestellte "Genealogie der Sitten", die von vielen als eine Beeinträchtigung empfunden wird. Vom Standpunkt der Evolution kommt es entscheidend auf den Reproduktionserfolg des einzelnen Wesens an, auf die Übertragung seiner Gene auf spätere Generationen, und das liefert den Maßstab für seine eigenen Fähigkeiten. Die Argumentation der Evolutionspsychologen fährt mit der Einführung von drei grundlegenden Begriffen fort: "kin selection" , reziproker Altruismus und indirekte Reziprozität. Jeder dieser Begriffe wird kritisch analysiert. Daraus folgt, daß der gegenwärtige Stand von Altruismus und Kooperation von der Evolutionsgeschichte nicht beeinflußt ist. Altruismus und Kooperation haben eine genetische Basis. Aber das haben alle menschlichen Eigenschaften, Bosheit genauso wie Kooperation. Daraus folgt nicht, daß die Motive für Kooperation stets dem Handelnden dienen. (shrink)

Cultural anthropologists and sociobiologists developed initially incommensurable approaches to explaining cooperation and altruism in human societies. When understood as complex cultural adaptations, however, scientific research programs are subject to piecemeal changes in the research programs driving scientific research. The emergence of new research programs in cultural evolution and group selection resulted. This transformation is examined with a focus on explanations for the origin and maintenance of human inequality. The transmission, modification, and selection of the complex cultural packages underlying egalitarianism (...) and hereditary inequality challenge both the focus on biological roots of hierarchy and the autonomous construction of cultures. (shrink)

Recent experimental research has revealed forms of human behavior involving interaction among unrelated individuals that have proven difficult to explain in terms of kin or reciprocal altruism. One such trait, 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. We present evidence supporting strong reciprocity as a schema for predicting and understanding altruism (...) in humans. We 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. Although most of the evidence we report is based on behavioral experiments, the same behaviors are regularly described in everyday life, for example, in wage setting by firms, tax compliance, and cooperation in the protection of local environmental public goods. D 2003 Elsevier Science Inc. All rights reserved. (shrink)

This study investigates an example of human altruism which is neither kin-directed nor reciprocal: giving to a panhandler. Data were collected on the proportions of passers-by who gave to panhandlers in Boston and Cambridge, Massachusetts. Three hypotheses were tested, each predicting that passers-by should behave “selfishly,” capitalizing on opportunities that, in an evolutionarily appropriate context, could increase mating success. Male passers-by, when alone, gave disproportionately to female panhandlers. Male passers-by, when in the company of a female partner, disproportionately avoided (...) giving to female panhandlers. Male passers-by in the company of a female partner did not “show off” by giving disproportionately to male panhandlers. (shrink)

Parochial altruism is manifested in the most violent of conflicts. Although it makes evolutionary sense for kin, many non-kin groups also behave parochially altruistically in response to threat from out-groups. It is possible that such non-kin groups share a sense of “fictive” kinship which encourages them to behave parochially altruistically for each other’s benefit. Our findings show that individuals not directly involved in a conflict approved of parochial altruism enacted by an in-group against an out-group more when the (...) out-group posed a threat to the in-group; however, this effect wasgreaterwhen the in-group members expressed fictive kinship by addressing each other using kinship metaphors such as “brothers.” Furthermore, although males approved of parochial altruism more than females, as the male warrior hypothesis would suggest, the effects of threat and kinship metaphor on approval of parochial altruism applied to both genders. These findings were replicated in an honour and non-honour culture. (shrink)

Altruistic behaviour, where it occurs in nature, is commonly assumed to belong to one or other of two generically different types. Either it is an example of "kin selected altruism" such as occurs between blood relatives – a worker bee risking her life to help her sister, for example, or a human father giving protection to his child. Or it is an example of "reciprocal altruism" such as occurs between non-relatives who have entered into a pact to exchange (...) favours – one male monkey supporting another unrelated male in a fight over a female, for example, or one bat who has food to spare offering it to another unrelated individual who is hungry. (shrink)

Evolutionists studying human cooperation disagree about how to best explain it. One view is that humans are predisposed to engage in costly cooperation and punishment of free-riders as a result of culture/gene coevolution via group selection. Alternatively, some researchers argue that context-specific cognitive mechanisms associated with traditional neo-Darwinian self- and kin-maximization models sufficiently explain all aspects of human cooperation and punishment. There has been a great deal of research testing predictions derived from both positions; still, researchers generally agree that more (...) naturalistic data are needed to complement mathematical modeling and laboratory and field experiments. Most of these data have been obtained from small-scale forager and other societies, but modern intentional communities offer another productive source of information. This exploratory study describes context-specific patterns of punishment in 46 American intentional communities that cast doubt on the prediction that people are predisposed to punish free-riders in naturalistic interactions. (shrink)

Altruism is one of the most studied topics in theoretical evolutionary biology. The debate surrounding the evolution of altruism has generally focused on the conditions under which altruism can evolve and whether it is better explained by kin selection or multilevel selection. This debate has occupied the forefront of the stage and left behind a number of equally important questions. One of them, which is the subject of this article, is whether the word “selection” in “kin selection” (...) and “multilevel selection” necessarily refers to “evolution by natural selection.” I show, using a simple individual-centered model, that once clear conditions for natural selection and altruism are specified, one can distinguish two kinds of evolution of altruism, only one of which corresponds to the evolution of altruism by natural selection, the other resulting from other evolutionary processes. (shrink)

We show how Richard Jeffrey's The Logic of Decision provides the proper formalism for calculating expected fitness for correlated encounters in general. As an illustration, some puzzles about kin selection are resolved.

We show how Richard Jeffrey’s The Logic of Decision provides the proper formalism for calculating expected fitness for correlated encounters in general. As an illustration, some puzzles about kin selection are resolved.

Euripides’ Alcestis (1959) raises the issue of ethical duties within families and exposes the romantic postures and rhetoric that can dominate such discussions. Should anybody be asked to sacrifice themselves or even undergo significant health risks for members of their own family? (An issue that is also relevant in considering our duties to future generations in terms of the earth we leave to them.) The issue that is dramatized to a heroic level in Alcestis arises in live organ and tissue (...) donation within a family and challenges the idea that families should be trusted to sort out solutions that they can all live with. Alcestis intensifies the debate because the sacrifice of one life for another is its topic but, in doing so, it exposes many traps lying in wait for ethicists and medical jurists who boldly enter such debates (where emotions create shifting ground on which angels fear to tread). (shrink)

My comments will focus on the second and third chapters of Sober’s book , which explore Darwin’s ideas about altruism, group selection and kin selection , and sex-ratio evolution . Sober makes a persuasive argument for his main claim: that Darwin was a subtler thinker on these topics than he is often taken to be. While there is much that I admire in Sober’s lucid discussion, I will focus on points of disagreement. Readers should note that this is not (...) the first time that Sober and I have disagreed on these issues .Sober begins his chapter on group selection with a brief history of the modern debate on the topic, which began in earnest in the 1960s. One of the key figures in this debate was George Williams, whose book Adaptation and Natural Selection helped convince many biologists that group selection was unlikely to be an important factor in evolution. Sober is critical of many of Williams’ arguments, though .. (shrink)

The puzzle of how altruism can evolve has been at the center of recent debates over Hamilton’s Rule, inclusive fitness, and kin-selection. In this paper, I use recent debates over altruism and Hamilton’s legacy as an example to illustrate a more general problem in evolutionary theory that has philosophical significance; I attempt to explain this significance and to draw a variety of conclusions about it. The problem is that specific behaviours and general concepts of organism agency and intentionality (...) are defined in terms of concepts of evolutionary “costs” and “benefits,” and these terms have determined the role that agency should play in evolutionary explanation. However, costs, benefits, and agency are not only or even best conceived through evolutionary effects in a biological context. The paper proceeds as follows: first, I explain how the issue of agency relates to the evolutionary puzzle of altruism. Next, I discuss how questions about agency have figured in recent debates over Hamilton’s legacy. In the final section, I argue that Denis Walsh’s “situated Darwinism,” which attempts to return the organism to central status in biological explanation, offers a more productive route for thinking about different forms of costs, benefits, and agency. Finally, I argue that the upshot of all this is that there may be many different, and equally valid, ways to express what organisms are doing and how they are behaving based on different currencies of cost and benefit—even if these may stand in some tension. I illustrate this through returning to the case of altruism and using examples to show that even in non-humans there can be many forms of altruism, even if they are not all biological altruism as defined in the conventional evolutionary terms. (shrink)

The question on how the diverse forms of cooperative behavior in humans and nonhuman animals could have evolved under the pressure of natural selection has been a challenge for evolutionary biology ever since Darwin himself. In this chapter, we briefly review and summarize results from the last 50 years of research on human and nonhuman cooperativeness from a theoretical (biology) and an experimental perspective (experimental economics). The first section presents six concepts from theoretical biology able to explain a variety of (...) forms of cooperativeness which evolved in many different species. These are kin selection, mutualism, reciprocity, green-beard altruism, costly signaling, and cultural group selection. These considerations are complemented by two short examples of evolved cooperative behavior, one from microbiology and one from ethology. The second main section focuses on recent experimental research on human cooperativeness. We present a brief review of factors known to impact individual human decision-making in social dilemmas, most prominently communication, punishment, reputation, and assortment. Our conclusion then draws attention to tasks for further research in this area. (shrink)

Reactive crying, displayed by children as a response to the distress of another, is described as a precursor of helping and caring. There are several stages during the transition from the innate, reactive cry to the intentional response. Children at the age of 6–14 months are able to control their reactive distress response, yet still respond to the distress of others by displaying distress behavior themselves. Two explanations are discussed. According to one explanation, children are confused about what happens to (...) the self and what happens to the other. This explanation is criticized for being based on misunderstandings of the nature of sensations. An alternative and more promising explanation is derived from kin selection theory. According to this explanation, the development of reactive crying and the transition to caring and helping have been shaped by different forces acting on paternally and maternally derived genes. (shrink)

Four models commonly employed in sharing analyses (reciprocal altruism [RA], tolerated scrounging [TS], costly signaling [CS], and kin selection [KS]) have common features which render rigorous testing of unique predictions difficult. Relaxed versions of these models are discussed in an attempt to understand how the underlying principles of delayed returns, avoiding costs, building reputation, and aiding biological kin interact in systems of sharing. Special attention is given to the interpretation of contingency measures that critically define some form of reciprocal (...) altruism. (shrink)

Inclusive fitness theory provides a compelling explanation for the evolution of altruism among kin. However, a completely satisfactory account of non-kin altruism is still lacking. The present study compared the level of altruism found among siblings with that found among friends and mates and sought to reconcile the findings with an evolutionary explanation for human altruism. Participants (163 males and 156 females) completed a questionnaire about help given to a sibling, friend, or mate. Overall, participants gave (...) friends and mates as much or more help than they gave siblings. However, as the cost of help increased, siblings received a progressively larger share of the help, whereas friends and mates received a progressively smaller share, despite the fact that participants were closer emotionally to friends and mates than they were to siblings. These findings help to explain the relative standing of friends and mates as recipients of altruistic aid. (shrink)

This paper begins with some reflections on my personal experiences with Ralph Wendell Burhoe during visits to the Chicago Center for Religion and Science. I learned to know Burhoe as an interested and kind person with enormous intellectual power. In this paper I argue that integration of different concepts was the chief focus of his thinking, expressing both an ethical and a dogmatic concern. If his theory of altruism contributes to the scientific investigations into the problem of trans‐kin (...) class='Hi'>altruism, then his vision of a scientific theology gains credibility. Such an integration is made plausible through the interpretation of altruism in light of Christian love. In fact, Burhoe's neonaturalistic approach may be a fertile resource for the dialogue between science and theology in Germany, and serve as an exemplar of Burhoe's important impact on this dialogue in general. (shrink)

Ralph Wendell Burhoe's legacy rests on a series of interrelated theories that deal with (1) the emergence of life within physical nature; (2) the symbiosis of genes and cultures in human evolution; (3) the central importance of the brain in this symbiosis; and (4) the function of religion within this evolutionary process to carry the traditions of trans‐kin altruism that make human civilization possible. These theories give rise to a number of issues that are of current importance. Burhoe's stature (...) is enhanced when one considers that these theories were first articulated by him in the 1970s, in reliance upon the work of J. Bronowski, Alfred E. Emerson, and Donald T. Campbell. (shrink)

What motivates grandparents to their altruism? We review answers from evolutionary theory, sociology, and economics. Sometimes in direct conflict with each other, these accounts of grandparental investment exist side-by-side, with little or no theoretical integration. They all account for some of the data, and none account for all of it. We call for a more comprehensive theoretical framework of grandparental investment that addresses its proximate and ultimate causes, and its variability due to lineage, values, norms, institutions (e.g., inheritance laws), (...) and social welfare regimes. This framework needs to take into account that the demographic shift to low fecundity and mortality in economically developed countries has profoundly altered basic parameters of grandparental investment. We then turn to the possible impact of grandparental acts of altruism, and examine whether benefits of grandparental care in industrialized societies may manifest in terms of less tangible dimensions, such as the grandchildren's cognitive and verbal ability, mental health, and well-being. Although grandparents in industrialized societies continue to invest substantial amounts of time and money in their grandchildren, we find a paucity of studies investigating the influence that this investment has on grandchildren in low-risk family contexts. Under circumstances of duress there is converging evidence that grandparents can provide support that helps to safeguard their children and grandchildren against adverse risks. We conclude by discussing the role that grandparents could play in what has been referred to as Europe's demographic suicide. (shrink)

Stove's article, 'So you think you are a Darwinian?'[ 1] was essentially an advertisement for his book, Darwinian Fairytales.[ 2] The central argument of the book is that Darwin's theory, in both Darwin's and recent sociobiological versions, asserts many things about the human and other species that are known to be false, but protects itself from refutation by its logical complexity. A great number of ad hoc devices, he claims, are used to protect the theory. If co operation is observed (...) where the theory predicts competition, then competition is referred to the time of the cavemen, or is reinterpreted as competition between some hidden entities like genes or abstract entities like populations. In a characteristic sally, Stove writes of the sociobiologists' oscillation on the meaning of kin altruism: Any discussion of altruism with an inclusive fitness theorist is, in fact, exactly like dealing with a pair of balloons connected by a tube, one balloon being the belief that kin altruism is an illusion, the other being the belief that kin altruism is caused by shared genes. If a critic puts pressure on the illusion balloon - perhaps by ridiculing the selfish theory of human nature - air is forced into the causal balloon. There is then an increased production of earnest causal explanations of why we love our children, why hymenopteran workers look after their sisters, etc., etc. Then, if the critic puts pressure on the causal balloon - perhaps about the weakness of sibling altruism compared with parental, or the absence of sibling altruism in bacteria - then the illusion balloon is forced to expand. There will now be an increased production of cynical scurrilities about parents manipulating their babies for their own advantage, and vice versa, and in general, about the Hobbesian bad times that are had by all. In this way critical pressure, applied to the theory of inclusive fitness at one point, can always be easily absorbed at another point, and the theory as a whole is never endangered.[ 3] Now, it is uncontroversial to assert that Darwinism is a logically complex theory, and that its relation to empirical evidence is distant and multi faceted. One does not directly observe chance genetic variations leading to the development of new species, or even continuous variations in the fossil record, but must rely on subtle arguments to the best explanation, scaling up from varieties to species, and so on.. (shrink)

The kin selection hypothesis posits that male androphilia (male sexual attraction to adult males) evolved because androphilic males invest more in kin, thereby enhancing inclusive fitness. Increased kin-directed altruism has been repeatedly documented among a population of transgendered androphilic males, but never among androphilic males in other cultures who adopt gender identities as men. Thus, the kin selection hypothesis may be viable if male androphilia was expressed in the transgendered form in the ancestral past. Using the Standard Cross-Cultural Sample (...) (SCCS), we examined 46 societies in which male androphilia was expressed in the transgendered form (transgendered societies) and 146 comparison societies (non-transgendered societies). We analyzed SCCS variables pertaining to ancestral sociocultural conditions, access to kin, and societal reactions to homosexuality. Our results show that ancestral sociocultural conditions and bilateral and double descent systems were more common in transgendered than in non-transgendered societies. Across the entire sample, descent systems and residence patterns that would presumably facilitate increased access to kin were associated with the presence of ancestral sociocultural conditions. Among transgendered societies, negative societal attitudes toward homosexuality were unlikely. We conclude that the ancestral human sociocultural environment was likely conducive to the expression of the transgendered form of male androphilia. Descent systems, residence patterns, and societal reactions to homosexuality likely facilitated investments in kin by transgendered males. Given that contemporary transgendered male androphiles appear to exhibit elevated kin-directed altruism, these findings further indicate the viability of the kin selection hypothesis. (shrink)

This chapter contains sections titled: Setting the Task The Moral Brain The First Layer: Kin Selection The Second Layer: Reciprocal Altruism A Third Layer: Indirect Reciprocity A Fourth Layer: Cultural Group Selection A Fifth Layer: The Moral Emotions Conclusion: From Moral Grammar to Moral Systems.

Recent analyses of food sharing in small-scale societies indicate that reciprocal altruism maintains interhousehold food transfers, even among close kin. In this study, matrix-based regression methods are used to test the explanatory power of reciprocal altruism, kin selection, and tolerated scrounging. In a network of 35 households in Nicaragua’s Bosawas Reserve, the significant predictors of food sharing include kinship, interhousehold distance, and reciprocity. In particular, resources tend to flow from households with relatively more meat to closely related households (...) with little, as predicted by kin selection. This generalization is especially true of household dyads with mother-offspring relationships, which suggests that studies of food sharing may benefit from distinctions between lineal and collateral kin. Overall, this analysis suggests that exchanges among kin are primarily associated with differences in need, not reciprocity. Finally, although large game is distributed widely, qualitative observations indicate that hunters typically do not relinquish control of the distribution in ways predicted by costly signaling theory. (shrink)

From mitochondria to meerkats, the natural world is full of spectacular examples of social behaviour. In the early 1960s W. D. Hamilton changed the way we think about how such behaviour evolves. He introduced three key innovations - now known as Hamilton's rule, kin selection, and inclusive fitness - and his pioneering work kick-started a research program now known as social evolution theory. This is a book about the philosophical foundations and future prospects of that program. [Note: only the Introduction (...) is available to download.]. (shrink)

Abstract. Scientists have long puzzled over how homosexual orientation has evolved, given the assumed low relative fitness of homosexual individuals compared to heterosexual individuals. A number of theoretical models for the evolution of homosexuality have been postulated including balance polymorphism, "Fertile females", hypervariability of DNA sequences, kin selection, and "parental manipulation". In this paper, I propose a new group-selection model for the evolution of homosexuality which offers two advantages over existing models: (1) its non-assumption of genetic determinism, and (2) its (...) lack of dependency on an inefficient altruism relation and family dynamics theory. (shrink)

This response outlines more reasons why we need the integrative framework of grandparental investments and intergenerational transfers that we advocated in the target article. We discusses obstacles that stand in the way of such a framework and of a better understanding of the effects of grandparenting in the developed world. We highlight new research directions that have emerged from the commentaries, and we end by discussing some of the things in our target article about which we may have been wrong.

The transfer of food among group members is a ubiquitous feature of small-scale forager and forager-agricultural populations. The uniqueness of pervasive sharing among humans, especially among unrelated individuals, has led researchers to evaluate numerous hypotheses about the adaptive functions and patterns of sharing in different ecologies. This article attempts to organize available cross-cultural evidence pertaining to several contentious evolutionary models: kin selection, reciprocal altruism, tolerated scrounging, and costly signaling. Debates about the relevance of these models focus primarily on the (...) extent to which individuals exert control over the distribution of foods they acquire, and the extent to which donors receive food or other fitness-enhancing benefits in return for shares given away. Each model can explain some of the variance in sharing patterns within groups, and so generalizations that ignore or deny the importance of any one model may be misleading. Careful multivariate analyses and cross-cultural comparisons of food transfer patterns are therefore necessary tools for assessing aspects of the sexual division of labor, human life history evolution, and the evolution of the family. This article also introduces a framework for better understanding variation in sharing behavior across small-scale traditional societies. I discuss the importance of resource ecology and the degree of coordination in acquisition activities as a key feature that influences sharing behavior. (shrink)

Jeffrey Tillman is perceptive in noticing that certain Protestant theologians have used evolutionary theory to become more sympathetic to Roman Catholic views of Christian love. But he is incorrect in saying that these formulations deemphasize a place for self-sacrifice in Christian love. Christian love defined as a strenuous equal-regard for both other and self also requires sacrificial efforts to restore love as equal-regard when finitude and sin undermine genuine mutuality and community.

Kinship and reciprocity are two main predictors of altruism. The ultimatum game has been used to study altruism in many small-scale societies. We used the ultimatum game to examine effects of individuals’ family and kin relations on altruistic behavior in a kin-based horticultural community in rural Dominica. Results show sex-specific effects of kin on ultimatum game play. Average coefficient of relatedness to the village was negatively associated with women’s ultimatum game proposals and had little effect on men’s proposals. (...) Number of brothers in the village was positively associated with men’s ultimatum game proposals and negatively associated with women’s proposals. Similarly, presence of father in the village was associated with higher proposals by men and lower proposals by women. We interpret the effect of brothers on men’s proposals as a consequence of local competition among brothers. We speculate that daughter-biased parental care in this community creates a sense of entitlement among women with brothers, which may explain the inverse relation between number of brothers and women’s ultimatum game proposals. The pattern of results may be consistent with how matrifocality affects cultural models of fairness differently along gender and family lines. (shrink)

Evolutionarily-minded scholars working on the most puzzling aspects of human cooperation-one-shot, anonymous interactions among non-kin where reputational information is not available-can be roughly divided into two camps. In the first, researchers argue for the existence of evolved capacities for genuinely altruistic human cooperation, and in their models emphasize the role of intergroup competition and selection, as well as group norms and markers of membership that reduce intragroup variability. Researchers in the second camp explain cooperation in terms of individual-level decision-making facilitated (...) by evolved cognitive mechanisms associated with well-established self- and kin-maximization models, as well as by ‘misfires’ that may result from these mechanisms interacting with novel environments. This essay argues that the manner in which culture provides information that de-anonymizes intragroup strangers suggests that neither evolved capacities for genuine altruism nor widespread misfires are necessary to account for anonymous, one-shot cooperation. (shrink)

Edward O. Wilson’s recent decision to abandon kin selection theory has sent shockwaves throughout the biological sciences. Over the past two years, more than a hundred biologists have signed letters protesting his reversal. Making sense of Wilson’s decision and the controversy it has spawned requires familiarity with the historical record. This entails not only examining the conditions under which kin selection theory first emerged, but also the organicist tradition against which it rebelled. In similar fashion, one must not only examine (...) Wilson’s long career, but also those thinkers who influenced him most, especially his intellectual grandfather, William Morton Wheeler (1865–1937). Wilson belongs to a long line of organicists, biologists whose research highlighted integration and coordination, many of whom struggled over the exact same biological riddles that have long defined Wilson’s career. Drawing inspiration (and sometimes ideas) from these intellectual forebears, Wilson is confident that he has finally identified the origin of the social impulse. (shrink)