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)

A modern evolutionary perspective emphasizing life history theory and behavioral ecology is brought to bear on the three core patterns of attachment that are identified in studies of infants and young children in the Strange Situation and adults using the Adult Attachment Interview. Mating and parenting correlates of secure/autonomous, avoidant/dismissing, and resistant/preoccupied attachment patterns are reviewed, and the argument is advanced that security evolved to promote mutually beneficial interpersonal relations and high investment parenting; that avoidant/dismissing attachment evolved to promote opportunistic (...) interpersonal relations and low-investment parenting; and that resistant/preoccupied attachment evolved to foster “helper-at-the-nest” behavior and indirect reproduction. (shrink)

1 Adaptationism is a research strategy that seeks to identify adaptations and the specific selective forces that drove their evolution in past environments. Since the mid-1970s, paleontologist Stephen J. Gould and geneticist Richard Lewontin have been critical of adaptationism, especially as applied toward understanding human behavior and cognition. Perhaps the most prominent criticism they made was that adaptationist explanations were analogous to Rudyard Kipling's Just So Stories. Since storytelling is an inherent part of science, the criticism refers to the acceptance (...) of stories without sufficient empirical evidence. In particular, Gould, Lewontin, and their colleagues argue that adaptationists often use inappropriate evidentiary standards for identifying adaptations and their functions, and that they often fail to consider alternative hypotheses to adaptation. Playing prominently in both of these criticisms are the concepts of constraint, spandrel, and exaptation. In this article we discuss the standards of evidence that could be used to identify adaptations and when and how they may be appropriately used. Moreover, building an empirical case that certain features of a trait are best explained by exaptation, spandrel, or constraint requires demonstrating that the trait's features cannot be better accounted for by adaptationist hypotheses. Thus, we argue that the testing of alternatives requires the consideration, testing, and systematic rejection of adaptationist hypotheses. Where possible, we illustrate our points with examples taken from human behavior and cognition. Key Words: adaptation; ADHD; brain allometry; constraint; epistemology; evolutionary psychology; exaptation; female orgasm ; optimization; special design; waist-hip ratio. Footnotes1 The authors contributed equally to this paper. Order of authorship was determined alphabetically. Correspondence may be addressed to any of the authors. (shrink)

With the discovery of conditioned reflexes by I. P. Pavlov, the possibilities for experimenting, following the example set by the classical, exact sciences, were made available to the behavioral sciences. Many psychologists hoped that the component parts of behavior had also been found from which the entire, multifaceted cosmos of behavior could then be constructed. An experimentally oriented psychology subsequently developed including the influential school of behaviorism. This first text on human ethology presents itself as a unified work, even though (...) not every area could be treated with equal depth. For example, a branch of ethology has developed in the past decade which places particular emphasis on ecology and population genetics. This field, known as sociobiology, has enriched discussion beyond the boundaries of behavioral biology through its stimulating, and often provocative, theses. After vigorous debates between behaviorists, anthropologists, and sociologists, we have entered a period of exchange of thoughts and a mutual approach, which in many instances has led to cooperative projects of researchers from different disciplines. This work offers a biological point of view for discussion and includes data from the author's cross-cultural work and research from the staff of his institute. It confirms, above all else, the astonishing unity of mankind and paints a basically positive picture of how we are moved by the same passions, jealousies, friendliness, and active curiosity. The need to understand ourselves has never been as great as it is today. An ideologically torn humanity struggles for its survival. Our species, does not know how it should compensate its workers, and it experiments with various economic systems, constitutions, and forms of government. It struggles for freedom and stumbles into newer conflicts. Population growth is apparently completely out of hand, and at the same time many resources are being depleted. We must consider our existence rationally in order to understand it, but certainly not with cold, calculating reason but with the warm feeling of a heart concerned for the welfare of later generations. (shrink)

Human females are generally reserved in their sexuality, in keeping with their heavy investment in reproduction. Males tend to be less reserved. Relative to males, however, females demonstrate more variability in sexuality and are more likely to inhibit or express high levels of sexuality. The heightened variability may in part originate with genetic mechanisms that predispose females toward greater variability. Menarche, menstrual cycles, menopause, food reactions, responses to living conditions, reactions to cultural factors, and responses to sexual stimuli and potential (...) mates are unique to or are more variable among females than males. There is a correlation between the variation expressed and female reproductive potential—females tend to shift dramatically from sexual inhibition to sexual expression. Females apparently track the quality of the environment and link their sexuality to reproductive opportunities. Successful male reproduction depends less on quality environments and more on the availability of females. In short, females track the environment; males track the females. (shrink)

Much research in the last two decades has demonstrated that human responses deviate from the performance deemed normative according to various models of decision making and rational judgment (e.g., the basic axioms of utility theory). This gap between the normative and the descriptive can be interpreted as indicating systematic irrationalities in human cognition. However, four alternative interpretations preserve the assumption that human behavior and cognition is largely rational. These posit that the gap is due to (1) performance errors, (2) computational (...) limitations, (3) the wrong norm being applied by the experimenter, and (4) a different construal of the task by the subject. In the debates about the viability of these alternative explanations, attention has been focused too narrowly on the modal response. In a series of experiments involving most of the classic tasks in the heuristics and biases literature, we have examined the implications of individual differences in performance for each of the four explanations of the normative/descriptive gap. Performance errors are a minor factor in the gap; computational limitations underlie non-normative responding on several tasks, particularly those that involve some type of cognitive decontextualization. Unexpected patterns of covariance can suggest when the wrong norm is being applied to a task or when an alternative construal of the task should be considered appropriate. Key Words: biases; descriptive models; heuristics; individual differences; normative models; rationality; reasoning. (shrink)

In most social species, position in the male social hierarchy and reproductive success are positively correlated; in humans, however, this relationship is less clear, with studies of traditional societies yielding mixed results. In the most economically advanced human populations, the adaptiveness of status vanishes altogether; social status and fertility are uncorrelated. These findings have been interpreted to suggest that evolutionary principles may not be appropriate for the explanation of human behavior, especially in modern environments. The present study tests the adaptiveness (...) of social status with actual mating and reproductive data in a representative sample of males from an industrial society. Reproductive success, even when assessed by a more reliable measure ofactualmale fertility than the one commonly used, fails to correlate with social status. In striking contrast, however, status is found to be highly correlated withpotentialfertility, as estimated from copulation frequency. Status thus accounts for as much as 62% of the variance in thisproximatecomponent of fitness. This pattern is remarkably similar to what is found in many traditional societies and would result in a substantial positive relationship between cultural and reproductive success in industrial populations were it not for the novel conditions imposed by contraception and monogamy. Various underlying mechanisms are suggested for these findings, illustrating the value of current behavioral and reproductive data in the study of adaptation. It is concluded that evolutionary explanations of human behavior remain entirely relevant in modern societies. (shrink)

Secular change in sex ratios is examined in relation to experience in the family. Two theoretical perspectives are outlined: Guttentag and Secord’s (1983) adaptation of social exchange theory, and sexual selection theory. Because of large-scale change in number of births and typical age differentials between men and women at marriage, low sex ratios at couple formation ages existed in the U.S. between 1965 and the early 1980s. The currently high sex ratios, however, will persist until the end of the century. (...) High sex ratios appear to be associated with lower divorce rates, male commitment to careers that promise economic rewards, male willingness to engage in child care, higher fertility, and higher rates of sexual violence. Sexual selection theory calls attention to intrasexual competition in the numerically larger sex. (shrink)

Although we find Gangestad & Simpson's argument intriguing, we question some of its underlying assumptions, including: (1) that fluctuating asymmetry (FA) is consistently heritable; (2) that symmetry is driving the effects; (3) that use of parametric tests with FA is appropriate; and (4) that a short-term mating strategy produces more offspring than a long-term strategy.

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)

The well-established finding that siblings growing up in the same family turn out to be very different from one another has puzzled psychologists and behavior geneticists alike. In this theoretical note we describe the possible ontogeny and phylogeny of a sibling differentiation mechanism. We suggest that sibling competition for parental investment results in sibling differentiation on a number of characteristics, producing different developmental trajectories within families. Variations in developmental trajectories within families may have had fitness advantages in ancestral environments because(a) (...) sibling competition for extrafamilial resources would be reduced and(b) these variations would be suited to environments containing a variety of niches or to changing environments. Predictions derived from this model and an example of an application to attachment theory are presented. (shrink)

The theory of sexual selection suggests several possible explanations for the development of standards of physical attractiveness in humans. Asymmetry and departures from average proportions may be markers of the breakdown of developmental stability. Supernormal traits may present age- and sex-typical features in exaggerated form. Evidence from social psychology suggests that both average proportions and (in females) “neotenous” facial traits are indeed more attractive. Using facial photographs from three populations (United States, Brazil, Paraguayan Indians), rated by members of the same (...) three populations, plus Russians and Venezuelan Indians, we show that age, average features, and (in females) feminine/neotenous features all play a role in facial attractiveness. (shrink)

Models of risk-taking as used in the social sciences may be improved by including concepts from life history theory, particularly environmental unpredictability and life expectancy. Community college students completed self-report questionnaires measuring these constructs along with several well-known correlates. The frequency of risk-taking was higher for those with higher future unpredictability beliefs and shorter lifespan estimates (as measured by the Future Lifespan Assessment developed for this study), and unpredictability beliefs remained significant after accounting for standard predictors, such as sex and (...) temperament. The results demonstrate the usefulness of applying concepts from life history theory to enhance our understanding of human behavior. (shrink)

In most cultures, extramarital sex is highly restricted for women. In most of those cultures, men transfer wealth to their own sons. In some cultures extramarital sex is not highly restricted for women, and in most of those cultures, men transfer wealth to their sisters' sons. Inheritance to sisters' sons ensures a man's biological relatedness to his heirs, and matrilineal inheritance has been posited as a male accommodation to cuckoldry—a paternity strategy—at least since the 15th century. However, longitudinal analysis of (...) the cumulative effect of female extramarital sex indicates that matrilineal inheritance is most advantageous for women and would be more accurately considered a grandmaternity strategy. That is, if the probability that men's putative children are their biological children is less than 1, the probabilistic degree of relatedness between a female and her matrilineal heirs is higher than her corresponding relatedness to her patrilineal heirs. The same holds true for men only if ρ is very low. The upshot is that for moderate levels of female extramarital sex, matrilineal inheritance, relative to patrilineal inheritance, is highly advantageous for women and disadvantageous for men. Consideration of female variance in reproductive success beyond the first generation, and of a man's network of obligation to the inclusive fitness of his relatives, suggests that although the establishment of matrilineal inheritance may require extremely high levels of female extramarital sex, once established, it is likely to be maintained at levels of ρ that reasonably characterize many societies in the ethnographic record. New analysis of previously published data shows a strong association between matrilineal inheritance and moderate to low probability of paternity, and an even stronger relationship between patrilineal inheritance and high probability of paternity. (shrink)

Evolutionary biology and feminism share a variety of philosophical and practical concerns. I have tried to describe how a perspective from both evolutionary biology and feminism can accelerate the achievement of goals for both feminists and evolutionary biologists. In an early section of this paper I discuss the importance of variation to the disciplines of evolutionary biology and feminism. In the section entitled “Control of Female Reproduction” I demonstrate how insight provided by participation in life as woman and also as (...) a feminist suggests testable hypotheses about the evolution of social behavior—hypotheses that are applicable to our investigations of the evolution of social behavior in nonhuman animals. In the section on “Deceit, Self-deception, and Patriarchal Reversals” I have overtly conceded that evolutionary biology, a scientific discipline, also represents a human cultural practice that, like other human cultural practices, may in parts and at times be characterized by deceit and self-deception. In the section on “Femininity” I have indicated how questions cast and answered and hypotheses tested from an evolutionary perspective can serve women and men struggling with sexist oppression. (shrink)

This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)

Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven “good genes” sexual selection leads to predictions about the nature of trade-offs that individuals make between mates’ (...) physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women’s preferences for men’s qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women. (shrink)

In the nineteenth century, Australian Aborigines were used by European scholars as an exemplar of early human forms, and have consequently featured as the crucial case study for generations of social theorists and anthropologists. Arguments about Aborigines examines controversial subjects such as family life, religion and ritual, and land rights through the prism of Aboriginal studies. Professor Hiatt's book will provide a valuable introduction to Aboriginal ethnography, and is a shrewd and stimulating history of the central questions in Aboriginal studies.

1. Some Women That Never Evolved 2. An Initial Inequality 3. Monogamous Primates: A Special Case 4. A Climate for Dominant Females 5. The Pros and Cons of Males 6. Competition and Bonding among Females 7. The Primate Origins of Female Sexuality 8. A Disputed Legacy.

In this classic, the world's expert on language and mind lucidly explains everything you always wanted to know about language: how it works, how children learn it, how it changes, how the brain computes it, and how it evolved. With deft use of examples of humor and wordplay, Steven Pinker weaves our vast knowledge of language into a compelling story: language is a human instinct, wired into our brains by evolution. The Language Instinct received the William James Book Prize from (...) the American Psychological Association and the Public Interest Award from the Linguistics Society of America. This edition includes an update on advances in the science of language since The Language Instinct was first published. (shrink)

Second, this collection of cognitive programs evolved in the Pleistocene to solve the adaptive problems regularly faced by our hunter-gatherer ancestors-...