Muscularity and Strength Affect Individual Variation in Self-Perception of Fighting Ability in Men

We Need Tough Brothers and Sisters in a Tight World: Cultural Tightness Leads to a Preference for Dominant and Muscular Leaders

Cultural tightness is characterized by strong norms and harsh punishments for deviant behaviors. We hypothesized that followers in tight (vs. loose) cultures would more strongly prefer muscular leaders. This hypothesis was confirmed across seven studies (N = 1,615) employing samples from the United States, the United Kingdom, and China. Using actual political leaders, we demonstrated that the tighter the state's culture was, the more muscular the elected governor was (Study 1). Temporarily situating participants in a tight (vs. loose) culture made them select a leader higher on muscularity but not on body fat, and the effects obtained occurred for both male and female leaders (Studies 2-3B). In addition, we demonstrated the mediating role of authoritarianism and a preference for a dominant leadership in this process (Studies 4-5B). These results demonstrate the importance of considering the interface between culture and the physical appearance of leaders.

Muscle-Building Exercise and Weapon Carrying and Physical Fighting Among U.S. Adolescent Boys

This study aimed to determine the association between engagement in muscle-building exercise and weapon carrying and physical fighting among adolescent boys. Cross-sectional data from the 2019 Youth Risk Behavior Survey (U.S.) were analyzed (N = 4120). Muscle-building exercise was assessed based on the number of days reported in the past 7 days, recategorized into four levels of engagement (no engagement [0 days], low engagement [1-2 days], moderate engagement [3-5 days], and high engagement [6-7 days]). Three forms of weapon carrying (general, on school grounds, gun carrying) and two forms of physical fighting (general, on school grounds) were assessed. Five logistic regression analyses with adjusted odds ratios (AOR) and 95% confidence intervals (CI) were used to determine the association between engagement in muscle-building exercise and weapon carrying and physical fighting, while adjusting for relevant demographic and control variables. Over 75% of participants reported engaging in muscle-building exercise. One in five (19.8%) participants reported any general weapon carrying in the past 30 days, 3.3% reported any weapon carrying at school in the past 30 days, 6.5% reported any gun carrying in the past 12 months, 28.0% reported any general physical fighting in the past 12 months, and 10.7% reported any physical fighting at school in the past 12 months. Logistic regressions showed that, compared to no engagement, participants who reported high engagement of muscle-building exercise had higher odds of general weapon carrying (AOR 2.18, 95% CI 1.54-3.07), gun carrying (AOR 2.12, 95% CI 1.23-3.64), and general physical fighting (AOR 2.07, 95% CI 1.53-2.79). These are novel findings that add to a growing literature related to engagement in muscularity-oriented behaviors among males. Prevention and intervention efforts are needed to ensure that adolescent boys engage in muscle-building exercise in ways that are not harmful and to reduce weapon carrying and physical fighting.

Long-Term Mating Orientation in Men: The Role of Socioeconomic Status, Protection Skills, and Parenthood Disposition

From an evolutionary perspective, phenotypic, social, and environmental factors help to shape the different costs and benefits of pursuing different reproductive strategies (or a mixture of them) from one individual to another. Since men's reproductive success is mainly constrained to women's availability, their mating orientations should be partially calibrated by features that women prefer in a potential partner. For long-term relationships, women prefer traits that signal access to resources, protection skills, and the willingness to share them. Using generalized linear models with laboratory data taken from a Chilean population (N = 197), this study aimed to test whether real and potential resources (measured as self-reported socioeconomic status), protection skills (measured as handgrip strength), and the willingness to provide resources and protection (measured as their disposition toward parenthood) are related to mating orientation in men. Our predictions were: (1) socioeconomic status would be positively associated with long-term and short-term mating orientation but for long-term-oriented individuals, this would be enhanced by having a more favorable parenthood disposition and (2) strength would be positively related to long-term mating orientation in men with higher socioeconomic status and a favorable disposition toward parenthood and it would have a positive and direct association with short-term mating orientation. Our results partially supported the first hypothesis, since men with higher socioeconomic status were more long-term oriented, but parenting disposition did not moderate this effect. Contrary to our expectations, socioeconomic status was not related to short-term mating orientation. Strength appeared not to be significant for long-term mating orientation, even interacting with other traits. However, strength by itself was powerfully linked with a short-term mating orientation. Our results suggest that only some individuals that are attractive for long-term relationships are indeed long-term oriented and may reflect the overall conflict of interests between mating strategies among sexes.

The Male Warrior Hypothesis: Testosterone-related Cooperation and Aggression in the Context of Intergroup Conflict

The Male Warrior Hypothesis (MWH) establishes that men's psychology has been shaped by inter-group competition to acquire and protect reproductive resources. In this context, sex-specific selective pressures would have favored cooperation with the members of one's group in combination with hostility towards outsiders. We investigate the role of developmental testosterone, as measured indirectly through static markers of prenatal testosterone (2D:4D digit ratio) and pubertal testosterone (body musculature and facial masculinity), on both cooperation and aggressive behavior in the context of intergroup conflict among men. Supporting the MWH, our results show that the intergroup conflict scenario promotes cooperation within group members and aggression toward outgroup members. Regarding the hormonal underpinnings of this phenomenon, we find that body musculature is positively associated with aggression and cooperation, but only for cooperation when context (inter-group competition) is taken into account. Finally, we did not find evidence that the formidability of the group affected individual rates of aggression or cooperation, controlling for individual characteristics.