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T K Shackelford

Publications and source records attributed to T K Shackelford.

8 recordsLinked to original sources
PubMed2001

Human sex differences in sexual psychology and behavior.

Because age and sex constitute the only distinct anatomical and physiological morphs (types) of the human species, universal sex differences ought to be expected. According to Darwinian theory, the most numerous sex differences are likely to be found in the domains of sexuality and reproduction. We first briefly review the basic model of the adaptationist program of modern Darwinian psychology. We then present evidence suggesting substantial sex differences in the following domains of sexual behavior: Mate preferences, interest in casual sex, interest in partner variety, jealousy, fantasy, sexual "plasticity," and magnitude of intrinsic sexual motivation. We then propose a program for research and explanation of sex differences that invokes both proximate and ultimate variables where appropriate. This program is based in modern Darwinian theory, neuroendocrinology, human genetics, and social and behavioral sciences. We conclude by considering sociopolitical implications of research on sex differences.

Adaptation, Psychological↗
PubMed2000

Wife killing: risk to women as a function of age.

Younger women, relative to older women, incur elevated risk of uxoricide-being murdered by their husbands. Some evolutionary theorists attribute this pattern to men's evolved sexual proprietariness, which inclines them to use violence to control women, especially those high in reproductive value. Other evolutionary theorists propose an evolved homicide module for wife killing. An alternative to both explanations is that young women experience elevated uxoricide risk as an incidental byproduct of marriage to younger men who commit the majority of acts of violence. We used a sample of 13,670 uxoricides to test these alternative explanations. Findings show that (a) reproductive-age women incur an elevated risk of uxoricide relative to older women; (b) younger men are overrepresented among uxoricide perpetrators; and (c) younger women, even when married to older men, still incur excess risk of uxoricide. Discussion examines competing explanations for uxoricide in light of these findings.

Adolescent↗
PubMed1998

Adaptations, exaptations, and spandrels.

Adaptation and natural selection are central concepts in the emerging science of evolutionary psychology. Natural selection is the only known causal process capable of producing complex functional organic mechanisms. These adaptations, along with their incidental by-products and a residue of noise, comprise all forms of life. Recently, S. J. Gould (1991) proposed that exaptations and spandrels may be more important than adaptations for evolutionary psychology. These refer to features that did not originally arise for their current use but rather were co-opted for new purposes. He suggested that many important phenomena--such as art, language, commerce, and war--although evolutionary in origin, are incidental spandrels of the large human brain. The authors outline the conceptual and evidentiary standards that apply to adaptations, exaptations, and spandrels and discuss the relative utility of these concepts for psychological science.

Adaptation, Physiological↗
PubMed1997

Human aggression in evolutionary psychological perspective.

This article proposes an evolutionary psychological account of human aggression. The psychological mechanisms underlying aggression are hypothesized to be context-sensitive solutions to particular adaptive problems of social living. Seven adaptive problems are proposed for which aggression might have evolved as a solution--co-opting the resources of others, defending against attack, inflicting costs on same-sex rivals, negotiating status and power hierarchies, deterring rivals from future aggression, deterring mates from sexual infidelity, and reducing resources expended on genetically unrelated children. We outline several of the contexts in which humans confront these adaptive problems and the evolutionary logic of why men are cross-culturally more violently aggressive than women in particular contexts. The article concludes with a limited review of the empirical evidence surrounding each of the seven hypothesized functions of aggression and discusses the status and limitations of the current evolutionary psychological account.

Aggression↗
PubMed1997

From vigilance to violence: mate retention tactics in married couples.

Although much research has explored the adaptive problems of mate selection and mate attraction, little research has investigated the adaptive problem of mate retention. We tested several evolutionary psychological hypotheses about the determinants of mate retention in 214 married people. We assessed the usage of 19 mate retention tactics ranging from vigilance to violence. Key hypothesized findings include the following: Men's, but not women's, mate retention positively covaried with partner's youth and physical attractiveness. Women's, but not men's, mate retention positively covaried with partner's income and status striving. Men's mate retention positively covaried with perceived probability of partner's infidelity. Men, more than women, reported using resource display, submission and debasement, and intrasexual threats to retain their mates. Women, more than men, reported using appearance enhancement and verbal signals of possession. Discussion includes an evolutionary psychological analysis of mate retention in married couples.

Adolescent↗
PubMed1997

Personality and mate preferences: five factors in mate selection and marital satisfaction.

Although personality characteristics figure prominently in what people want in a mate, little is known about precisely which personality characteristics are most important, whether men and women differ in their personality preferences, whether individual women or men differ in what they want, and whether individuals actually get what they want. To explore these issues, two parallel studies were conducted, one using a sample of dating couples (N = 118) and one using a sample of married couples (N = 216). The five-factor model, operationalized in adjectival form, was used to assess personality characteristics via three data sources-self--report, partner report, and independent interviewer reports. Participants evaluated on a parallel 40-item instrument their preferences for the ideal personality characteristics of their mates. Results were consistent across both studies. Women expressed a greater preference than men for a wide array of socially desirable personality traits. Individuals differed in which characteristics they desired, preferring mates who were similar to themselves and actually obtaining mates who embodied what they desired. Finally, the personality characteristics of one's partner significantly predicted marital and sexual dissatisfaction, most notably when the partner was lower on Agreeableness, Emotional Stability, and Intellect-Openness than desired.

Choice Behavior↗
PubMed1997

Facial asymmetry as an indicator of psychological, emotional, and physiological distress.

Fluctuating asymmetry (FA) is deviation from bilateral symmetry in morphological traits with asymmetry values that are normally distributed with a mean of 0. FA is produced by genetic or environmental perturbations of developmental design and may play a role in human sexual selection. K. Grammer and R. Thornhill (1994) found that facial FA negatively covaries with observer ratings of attractiveness, dominance, sexiness, and health. Using self-reports, observer ratings, daily diary reports, and psychophysiological measures, the authors assessed the relationship between facial FA and health in 2 samples of undergraduates (N = 101). Results partially replicate and extend those of K. Grammer and R. Thornhill (1994) and suggest that facial FA may signal psychological, emotional, and physiological distress. Discussion integrates the authors' findings with previous research on FA and suggests future research needed to clarify the role of FA in human sexual selection.

Adolescent↗