Bo Winegard

A sex difference in the predisposition for physical competition: males play sports much more than females even in the contemporary U.S.

Much evidence indicates that men experienced an evolutionary history of physical competition, both one-on-one and in coalitions. We thus hypothesized that, compared to girls and women, boys and men will possess a greater motivational predisposition to be interested in sports, especially team sports. According to most scholars, advocacy groups, and the United States courts, however, this hypothesis is challenged by modest sex differences in organized school sports participation in the contemporary U.S., where females comprise 42% of high school participants and 43% of intercollegiate participants. We conducted three studies to test whether organized school sports participation data underestimate the actual sex difference in sports participation. Study 1 analyzed the American Time Use Survey, which interviewed 112,000 individuals regarding their activities during one day. Females accounted for 51% of exercise (i.e., non-competitive) participations, 24% of total sports participations, and 20% of team sports participations. These sex differences were similar for older and younger age groups. Study 2 was based on systematic observations of sports and exercise at 41 public parks in four states. Females accounted for 37% of exercise participations, 19% of individual sports participations, and 10% of team sports participations. Study 3 involved surveying colleges and universities about intramural sports, which primarily consist of undergraduate participation in team sports. Across 34 institutions, females accounted for 26% of registrations. Nine institutions provided historical data, and these did not indicate that the sex difference is diminishing. Therefore, although efforts to ensure more equitable access to sports in the U.S. (i.e., Title IX) have produced many benefits, patterns of sports participation do not challenge the hypothesis of a large sex difference in interest and participation in physical competition.

Who Is the Fairest One of All? How Evolution Guides Peer and Media Influences on Female Body Dissatisfaction

Much attention has focused on the influence of media images of thin women on body dissatisfaction among female viewers. Disagreement exists regarding the nature of media influences, with meta-analytic results suggesting only small effect sizes. Fewer researchers have focused on the role of peer influences and peer competition on female body dissatisfaction. Furthermore, the relation between body dissatisfaction and eating disorders may be more complex than is often implied in the media effects literature. Links between body dissatisfaction and eating disorders may be overstated, and some eating disorders, primarily anorexia nervosa, may not always be motivated primarily by body dissatisfaction. The current paper discusses these issues from an evolutionary perspective, examining how sociocultural forces influence the intensity of female competition and how such competition effects body dissatisfaction.

Grief Functions as an Honest Indicator of Commitment

Grief is a puzzling phenomenon. It is often costly and prolonged, potentially increasing mortality rates, drug abuse, withdrawal from social life, and susceptibility to illness. These costs cannot be repaid by the deceased and therefore might appear wasted. In the following article, we propose a possible solution. Using the principles of social selection theory, we argue that an important selective pressure behind the human grief response was the social decisions of other humans. We combine this with insights from signaling theory, noting that grief shares many properties with other hard-to-fake social signals. We therefore contend that grief was shaped by selective forces to function as a hard-to-fake signal of (a) a person’s propensity to form strong, non-utilitarian bonds and (b) a person’s current level of commitment to a group or cause. This theory explains many of the costly symptoms of grief and provides a progressive framework for future research.

The Influence of Heritability, Neuroticism, Maternal Warmth and Media Use on Disordered Eating Behaviors: A Prospective Analysis of Twins

The relative impact of genetic and social influences on disordered eating behaviors (DEB) including binging, purging, excessive dieting and negative self-evaluations about weight remain an issue of debate. The current study sought to examine the relative influence of genetic and social influences on DEB. A 7-year prospective analysis of 580 monozygotic (MZ) and dizygotic (DZ) twins was conducted. Estimates of heritability of DEB were obtained using the DF Analysis Model. Regression equations revealed the relative predictive value of sibling’s DEB, neurotic personality, maternal warmth and television and video game exposure on DEB. Heritability estimates for DEB were 0.40 for females and 0.48 for males. Among MZ and DZ twin pairs, female sex, neurotic personality and a genetic variable component, but not maternal warmth or school related problems, predicted DEB. Contrary to the expectations of media effects theory, greater media use was associated with lower DEB among DZ twins and had no influence on MZ twins. These results indicate that DEB is highly heritable and that personality variables may play an important role in the formation of DEB. This suggests that it is important to control for genetic variables when analyzing risk factors for DEB.

Reflections on the Evolution of Human Sex Differences: Social Selection and the Evolution of Competition Among Women

Darwin’s (1871) sexual selection, in particular male–male competition over mates and female choice of mating partners, has successfully guided research on sex differences across hundreds of species, including our own. One consequence of the success of sexual selection has been a relative indifference to other pressures that can result in the evolution of sex differences. In recent years, female–female competition over resources other than mates has captured the attention of evolutionary biologists. We illustrate how this form of competition, termed social selection, has operated to create sex differences in several nonhuman species and then apply it to female–female competition in humans. We propose that a combination arranged marriages, which will lessen direct competition for marriage partners, and polygyny created a unique social context within which female–female competition evolved, specifically competition among co-wives for access to resources controlled by their husband and competitive promotion of their children’s future reproductive prospects vis-a-vis the prospects of the children of co-wives. Competition among co-wives is more subtle—termed relational aggression—than that among men and involves the subtle manipulation of social relationships and psychological harassment of co-wives and their children. We review evidence related to the psychological and reproductive costs of conflicts with co-wives and argue that this competition contributed to girls’ and women’s advantages over boys and men for cognitive competencies, such as sensitivity to facial expressions, that support relational aggression.

Eastwood’s brawn and Einstein’s brain: An evolutionary account of dominance, prestige, and precarious manhood.

Researchers have theorized that manhood is a precarious social status that requires effort to achieve. Because of this, men whose manhood is threatened react with a variety of compensatory behaviors and cognitions such as aggression, support for hierarchy, low tolerance for homosexuality, and support for war. In the following article, we argue that the precarious status of manhood is a result of evolutionary propensities and cultural forces. Specifically, men evolved in dominance hierarchies and therefore, display honest signals of strength and vigor to dissuade other men from fighting them. However, men also evolved in large, prestige-based coalitions and compete against each other to display traits that enhance a coalition. These traits can vary from physical prowess and aggression to intelligence and empathy. As culture becomes more pluralistic and modernized, traditional notions of manhood become less important and alternative avenues for achieving status become available.

Misrepresentations of Evolutionary Psychology in Sex and Gender Textbooks

Evolutionary psychology has provoked controversy, especially when applied to human sex differences. We hypothesize that this is partly due to misunderstandings of evolutionary psychology that are perpetuated by undergraduate sex and gender textbooks. As an initial test of this hypothesis, we develop a catalog of eight types of errors and document their occurrence in 15 widely used sex and gender textbooks. Consistent with our hypothesis, of the 12 textbooks that discussed evolutionary psychology, all contained at least one error, and the median number of errors was five. The most common types of errors were “Straw Man,” “Biological Determinism,” and “Species Selection.” We conclude by suggesting improvements to undergraduate sex and gender textbooks.

If You’ve Got It, Flaunt It: Humans Flaunt Attractive Partners to Enhance Their Status and Desirability

Mating decisions are influenced by conspecifics’ mate choices in many species including humans. Recent research has shown that women are more attracted to men with attractive putative partners than those with less attractive partners. We integrate these findings with traditional accounts of social signaling and test five hypotheses derived from it. In our study, 64 men and 75 women were paired with attractive and unattractive opposite-sex putative partners and asked whether they would prefer to give surveys to peers or to older adults. Consistent with predictions, both men and women wanted to show off (flaunt) attractive partners by administering surveys to peers and both men and women wanted to hide (conceal) unattractive partners from peers by administering surveys to older adults. These decisions were mediated by how participants expected others to evaluate their status and desirability when they administered the surveys, consistent with partners serving a social signaling function in humans.

Death Before Dishonor: Incurring Costs to Protect Moral Reputation

Predicated on the notion that people’s survival depends greatly on participation in cooperative society, and that reputation damage may preclude such participation, four studies with diverse methods tested the hypothesis that people would make substantial sacrifices to protect their reputations. A “big data” study found that maintaining a moral reputation is one of people’s most important values. In making hypothetical choices, high percentages of “normal” people reported preferring jail time, amputation of limbs, and death to various forms of reputation damage (i.e., becoming known as a criminal, Nazi, or child molester). Two lab studies found that 30% of people fully submerged their hands in a pile of disgusting live worms, and 63% endured physical pain to prevent dissemination of information suggesting that they were racist. We discuss the implications of reputation protection for theories about altruism and motivation.

Forget the Folk: Conditions for Compatibilism

For years, experimental philosophers have attempted to discern whether lay people believe free will is compatible with a deterministic universe. In the current article, we argue that these attempts are likely misguided because (1) lay people do not have stable, logically rigorous notions of free will and (2) people are strongly motivated to preserve moral responsibility. Five studies support this hypothesis. In Studies 1-3, participants’ compatibilist judgments were influenced by logically irrelevant factors, including the salience of the possible reality of determinism (Study 1), the salience of moral implications (Studies 2-3a), and the order of argument presentation (Studies 3a-3b). In Study 4, people reported that immaterial souls were compatible with scientific determinism, most strongly among immaterial soul believers. In Study 5, participants evaluated information about the capacities of primates in a biased manner favoring the existence of human free will. Recommendations for future work are discussed.