Anecdotal evidence from many hunter-gatherer societies suggests that successful hunters experience higher prestige and greater reproductive success. Detailed quantitative data on these patterns are now available for five widely dispersed cases (Ache, Hadza, !Kung, Lamalera, and Meriam) and indicate that better hunters exhibit higher age-corrected reproductive success than other men in their social group. Leading explanations to account for this pattern are: (1) direct provisioning of hunters’ wives and offspring, (2) dyadic reciprocity, (3) indirect reciprocity, (4) costly signaling, and (5) (...) phenotypic correlation. I examine the qualitative and quantitative evidence bearing on these explanations and conclude that although none can be definitively rejected, extensive and apparently unconditional sharing of large game somewhat weakens the first three explanations. The costly signaling explanation has support in some cases, although the exact nature of the benefits gained from mating or allying with or deferring to better hunters needs further study. (shrink)

The evolutionary origin of human pair-bonds is uncertain. One hypothesis, supported by data from forgers, suggests that pair-bonds function to provision mothers and dependent offspring during lactation. Similarly, public health data from large-scale industrial societies indicate that single mothers tend to wean their children earlier than do women living with a mate. Here we examine relations between pair-bond stability, alloparenting, and cross-cultural trends in breastfeeding using data from 58 “traditional” societies in the Standard Cross-Cultural Sample (SCCS). Analyses show that stable (...) conjugal relationships were associated with significantly later weaning among the societies in the SCCS. The relationship between pair-bond stability and age at weaning was not mediated by women’s ability to provision themselves or women’s kin support. Availability of alloparental care was also inversely related to age at weaning, and the association was not significantly reduced after controlling for frequency of divorce. This study indicates that among a woman’s kin relationships, a pair-bond with a child’s father is especially supportive of breastfeeding. These cross-cultural findings are further evidence that human pair-bonds may have evolved to support lactation. (shrink)

In men, high levels of endogenous testosterone (T) seem to encourage behavior intended to dominate other people. Sometimes dominant behavior is aggressive, its apparent intent being to inflict harm on another person, but often dominance is expressed nonaggressively. Sometimes dominant behavior takes the form of antisocial behavior, including rebellion against authority and law breaking. Measurement of T at a single point in time, presumably indicative of a man's basal T level, predicts many of these dominant or antisocial behaviors. T not (...) only affects behavior but also responds to it. The act of competing for dominant status affects male T levels in two ways. First, T rises in the face of a challenge, as if it were an anticipatory response to impending competition. Second, after the competition, T rises in winners and declines in losers. Thus, there is a reciprocity between T and dominance behavior, each affecting the other. We contrast a reciprocal model, in which T level is variable, acting as both a cause and effect of behavior, with a basal model, in which T level is assumed to be a persistent trait that influences behavior. An unusual data set on Air Force veterans, in which data were collected four times over a decade, enables us to compare the basal and reciprocal models as explanations for the relationship between T and divorce. We discuss sociological implications of these models. (shrink)

How do we go about weighing evidence, testing hypotheses, and making inferences? The model of " inference to the best explanation " -- that we infer the hypothesis that would, if correct, provide the best explanation of the available evidence--offers a compelling account of inferences both in science and in ordinary life. Widely cited by epistemologists and philosophers of science, IBE has nonetheless remained little more than a slogan. Now this influential work has been thoroughly revised and updated, and features (...) a new introduction and two new chapters. Inference to the Best Explanation is an unrivaled exposition of a theory of particular interest in the fields both of epistemology and the philosophy of science. (shrink)

In this paper, I critique arguments made by philosopher David Buller against central evolutionary-psychological explanations of human mating. Specifically, I aim to rebut his criticisms of Evolutionary Psychology regarding women's long-term mating preferences for high-status men; the evolutionary rationale behind men's provisioning of women; men's mating preferences for young women; women's adaptation for extra-pair sex; the sex-differentiated evolutionary theory of human jealousy; and the notion of mate value. In sum, I aim to demonstrate that Buller's arguments contra Evolutionary Psychologists are (...) left wanting. (shrink)

The finding that women are attracted to men older than themselves whereas men are attracted to relatively younger women has been explained by social psychologists in terms of economic exchange rooted in traditional sex-role norms. An alternative evolutionary model suggests that males and females follow different reproductive strategies, and predicts a more complex relationship between gender and age preferences. In particular, males' preferences for relatively younger females should be minimal during early mating years, but should become more pronounced as the (...) male gets older. Young females are expected to prefer somewhat older males during their early years and to change less as they age. We briefly review relevant theory and present results of six studies testing this prediction. Study 1 finds support for this gender-differentiated prediction in age preferences expressed in personal advertisements. Study 2 supports the prediction with marriage statistics from two U.S. cities. Study 3 examines the cross-generational robustness of the phenomenon, and finds the same pattern in marriage statistics from 1923. Study 4 replicates Study 1 using matrimonial advertisements from two European countries, and from India. Study 5 finds a consistent pattern in marriages recorded from 1913 through 1939 on a small island in the Philippines. Study 6 reveals the same pattern in singles advertisements placed by financially successful American women and men. We consider the limitations of previous normative and evolutionary explanations of age preferences and discuss the advantages of expanding previous models to include the life history perspective. (shrink)

Andrews et al. effectively argue that, despite prominent criticism, adaptationism can be a viable research strategy. We agree. In our complementary commentary, we discuss the neglected method of inference to the best explanation and argue that it is a valuable addition to the adaptationist's methodological practice.

During human evolutionary history, there were “trade-offs” between expending time and energy on child-rearing and mating, so both men and women evolved conditional mating strategies guided by cues signaling the circumstances. Many short-term matings might be successful for some men; others might try to find and keep a single mate, investing their effort in rearing her offspring. Recent evidence suggests that men with features signaling genetic benefits to offspring should be preferred by women as short-term mates, but there are trade-offs (...) between a mate's genetic fitness and his willingness to help in child-rearing. It is these circumstances and the cues that signal them that underlie the variation in short- and long-term mating strategies between and within the sexes. Key Words: conditional strategies; evolutionary psychology; fluctuating asymmetry; mating; reproductive strategies; sexual selection. (shrink)

In recent times evolutionary psychologists have offered adaptation explanations for a wide range of human psychological characteristics. Critics, however, have argued that such endeavors are problematic because the appropriate evidence required to demonstrate adaptation is unlikely to be forthcoming, therefore severely limiting the role of the adaptationist program in psychology. More specifically, doubts have been raised over both the methodology employed by evolutionary psychologists for studying adaptations and about the possibility of ever developing acceptably rigorous evolutionary explanations of human psychological (...) phenomena. We argue that by employing a wide range of methods for inferring adaptation and by adopting an inference to the best explanation strategy for evaluating adaptation explanations, these two doubts can be adequately addressed. We illustrate how this approach can be fruitfully employed in evaluating claims about the evolutionary origins of language, and conclude with a brief discussion of the future of evolutionary psychology. (shrink)

Contemporary mate preferences can provide important clues to human reproductive history. Little is known about which characteristics people value in potential mates. Five predictions were made about sex differences in human mate preferences based on evolutionary conceptions of parental investment, sexual selection, human reproductive capacity, and sexual asymmetries regarding certainty of paternity versus maternity. The predictions centered on how each sex valued earning capacity, ambition— industriousness, youth, physical attractiveness, and chastity. Predictions were tested in data from 37 samples drawn from (...) 33 countries located on six continents and five islands. For 27 countries, demographic data on actual age at marriage provided a validity check on questionnaire data. Females were found to value cues toresource acquisitionin potential mates more highly than males. Characteristics signalingreproductive capacitywere valued more by males than by females. These sex differences may reflect different evolutionary selection pressures on human males and females; they provide powerful cross-cultural evidence of current sex differences in reproductive strategies. Discussion focuses on proximate mechanisms underlying mate preferences, consequences for human intrasexual competition, and the limitations of this study. (shrink)

For some evolutionary psychology is merely a field of inquiry, but for others it is a robust paradigm involving specific theories about the nature and evolution of the human mind. Proponents of this paradigm claim to have made several important discoveries regarding the evolved architecture of the mind. Highly publicized discoveries include a cheater-detection module, a psychological sex difference in jealousy, and motivational mechanisms underlying parental love and its lapses, which purportedly result in child maltreatment. In this article, I argue (...) that the empirical evidence for these ‘discoveries’ is inconclusive, at best. I suggest that, as the reigning paradigm in evolutionary psychology has produced questionable results, the evolutionary study of human psychology is still in need of a guiding paradigm. (shrink)

Using questionnaire data completed by 170 men, we examine variation in paternal investment in relation to the trade-off between mating and parenting. We found that as men’s self-perceived mate value increases, so does their mating effort, and in turn, as mating effort increases, paternal investment decreases. This study also simultaneously examined the influence on parental investment of men’s mating effort, men’s perception of their mates’ fidelity, and their perceived resemblance to their offspring. All predicted investment. The predictors of investment are (...) also tested independently for men who are still in a relationship with the mother of their children and those that are separated from her. Finally we examine how self-perceived mate value affects how men respond to variation in paternity confidence. Men with a self-perceived low mate value were less likely to respond to lowered mate fidelity by reducing their parental investment compared with men with a self-perceived high mate value. (shrink)

Human beings, like other organisms, are the products of evolution. Like other organisms, we exhibit traits that are the product of natural selection. Our psychological capacities are evolved traits as much as are our gait and posture. This much few would dispute. Evolutionary psychology goes further than this, claiming that our psychological traits -- including a wide variety of traits, from mate preference and jealousy to language and reason -- can be understood as specific adaptations to ancestral Pleistocene conditions. In (...) Evolutionary Psychology as Maladapted Psychology, Robert Richardson takes a critical look at evolutionary psychology by subjecting its ambitious and controversial claims to the same sorts of methodological and evidential constraints that are broadly accepted within evolutionary biology. The claims of evolutionary psychology may pass muster as psychology; but what are their evolutionary credentials? Richardson considers three ways adaptive hypotheses can be evaluated, using examples from the biological literature to illustrate what sorts of evidence and methodology would be necessary to establish specific evolutionary and adaptive explanations of human psychological traits. He shows that existing explanations within evolutionary psychology fall woefully short of accepted biological standards. The theories offered by evolutionary psychologists may identify traits that are, or were, beneficial to humans. But gauged by biological standards, there is inadequate evidence: evolutionary psychologists are largely silent on the evolutionary evidence relevant to assessing their claims, including such matters as variation in ancestral populations, heritability, and the advantage offered to our ancestors. As evolutionary claims they are unsubstantiated. Evolutionary psychology, Richardson concludes, may offer a program of research, but it lacks the kind of evidence that is generally expected within evolutionary biology. It is speculation rather than sound science -- and we should treat its claims with skepticism. (shrink)

Was human nature designed by natural selection in the Pleistocene epoch? The dominant view in evolutionary psychology holds that it was -- that our psychological adaptations were designed tens of thousands of years ago to solve problems faced by our hunter-gatherer ancestors. In this provocative and lively book, David Buller examines in detail the major claims of evolutionary psychology -- the paradigm popularized by Steven Pinker in The Blank Slate and by David Buss in The Evolution of Desire -- and (...) rejects them all. This does not mean that we cannot apply evolutionary theory to human psychology, says Buller, but that the conventional wisdom in evolutionary psychology is misguided.Evolutionary psychology employs a kind of reverse engineering to explain the evolved design of the mind, figuring out the adaptive problems our ancestors faced and then inferring the psychological adaptations that evolved to solve them. In the carefully argued central chapters of Adapting Minds, Buller scrutinizes several of evolutionary psychology's most highly publicized "discoveries," including "discriminative parental solicitude". Drawing on a wide range of empirical research, including his own large-scale study of child abuse, he shows that none is actually supported by the evidence.Buller argues that our minds are not adapted to the Pleistocene, but, like the immune system, are continually adapting, over both evolutionary time and individual lifetimes. We must move beyond the reigning orthodoxy of evolutionary psychology to reach an accurate understanding of how human psychology is influenced by evolution. When we do, Buller claims, we will abandon not only the quest for human nature but the very idea of human nature itself. (shrink)

How do we go about weighing evidence, testing hypotheses, and making inferences? According to the model of _Inference to the Best Explanation_, we work out what to infer from the evidence by thinking about what would actually explain that evidence, and we take the ability of a hypothesis to explain the evidence as a sign that the hypothesis is correct. In _Inference to the Best Explanation_, Peter Lipton gives this important and influential idea the development and assessment it deserves. The (...) second edition has been substantially enlarged and reworked, with a new chapter on the relationship between explanation and Bayesianism, and an extension and defence of the account of contrastive explanation. It also includes an expanded defence of the claims that our inferences really are guided by diverse explanatory considerations, and that this pattern of inference can take us towards the truth. This edition of _Inference to the Best Explanation_ has also been updated throughout and includes a new bibliography. (shrink)

Human beings, like other organisms, are the products of evolution. Like other organisms, we exhibit traits that are the product of natural selection. Our psychological capacities are evolved traits as much as are our gait and posture. This much few would dispute. Evolutionary psychology goes further than this, claiming that our psychological traits -- including a wide variety of traits, from mate preference and jealousy to language and reason -- can be understood as specific adaptations to ancestral Pleistocene conditions. In (...) Evolutionary Psychology as Maladapted Psychology, Robert Richardson takes a critical look at evolutionary psychology by subjecting its ambitious and controversial claims to the same sorts of methodological and evidential constraints that are broadly accepted within evolutionary biology. The claims of evolutionary psychology may pass muster as psychology; but what are their evolutionary credentials? Richardson considers three ways adaptive hypotheses can be evaluated, using examples from the biological literature to illustrate what sorts of evidence and methodology would be necessary to establish specific evolutionary and adaptive explanations of human psychological traits. He shows that existing explanations within evolutionary psychology fall woefully short of accepted biological standards. The theories offered by evolutionary psychologists may identify traits that are, or were, beneficial to humans. But gauged by biological standards, there is inadequate evidence: evolutionary psychologists are largely silent on the evolutionary evidence relevant to assessing their claims, including such matters as variation in ancestral populations, heritability, and the advantage offered to our ancestors. As evolutionary claims they are unsubstantiated. Evolutionary psychology, Richardson concludes, may offer a program of research, but it lacks the kind of evidence that is generally expected within evolutionary biology. It is speculation rather than sound science -- and we should treat its claims with skepticism. (shrink)

In the carefully argued central chapters of Adapting Minds, Buller scrutinizes several of evolutionary psychology's most highly publicized "...