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Students’ perceptions of school safety and experiences with bullying were examined in a large Canadian cohort of 5,493 girls and 5,659 boys in Grades 4 to 12. Results indicate notable differences in when and where students felt safe based on their own perceptions of safety and their own experiences with bullying, particularly across elementary and secondary schools. For elementary students, especially those involved in bullying, the playground/school yard and outside recess/break time were particularly hazardous, whereas for secondary students involved in bullying, the hallways, school lunchroom/cafeteria, and outside recess/break were considered especially dangerous. The commonality across student-identified unsafe areas is that they tend to not be well supervised by school personnel. Accordingly, the present results underscore the need to increase adult supervision in areas in which an overwhelming majority of students report feeling unsafe.

In order for non-kin altruism to evolve, altruists must receive fitness benefits for their actions that outweigh the costs. Several researchers have suggested that altruism is a costly signal of desirable qualities, such that it could have evolved by sexual selection. In two studies, we show that altruism is broadly linked with mating success. In Study 1, participants who scored higher on a self-report altruism measure reported they were more desirable to the opposite sex, as well as reported having more sex partners, more casual sex partners, and having sex more often within relationships. Sex moderated some of these relationships, such that altruism mattered more for men's number of lifetime and casual sex partners. In Study 2, participants who were willing to donate potential monetary winnings (in a modified dictator dilemma) reported having more lifetime sex partners, more casual sex partners, and more sex partners over the past year. Men who were willing to donate also reported having more lifetime dating partners. Furthermore, these patterns persisted, even when controlling for narcissism, Big Five personality traits, and socially desirable responding. These results suggest that altruists have higher mating success than non-altruists and support the hypothesis that altruism is a sexually selected costly signal of difficult-to-observe qualities.

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Adolescent peer-aggression has recently been considered from the evolutionary perspective of intrasexual competition for mates. We tested the hypothesis that peernominated physical aggression, indirect aggression, along with self-reported bullying behaviors at Time 1 would predict Time 2 dating status (one year later), and that Time 1 peer-and self-reported peer victimization would negatively predict Time 2 dating status. Participants were 310 adolescents who were in grades 6 through 9 (ages 11-14) at Time 1. Results showed that for both boys and girls, peer-nominated indirect aggression was predictive of dating one year later even when controlling for age, peer-rated attractiveness, and peer-perceived popularity, as well as initial dating status. For both sexes, self-reported peer victimization was negatively related to having a dating partner at Time 2. Findings are discussed within the framework of intrasexual competition.

Indirect aggression is considered an evolutionarily adaptive mechanism that can improve female mating success. It has been hypothesized that indirect aggression toward romantic partners and peers is used more frequently by females who make appearance-based comparisons and that these relationships are mediated by jealousy. Females (N = 528) currently in romantic relationships were surveyed. Results confirmed females who made more frequent appearance comparisons aggressed more often toward partners and peers. Low-comparing females reported being more frequent targets of peer indirect aggression. Jealousy partially mediated the relationships between making frequent attractiveness comparisons and indirect aggression. Results are discussed as effort allocated toward deterring partner defection and fending off rivals, and the role of emotion as a motivational influence for aggression.

Mate availability has been shown to influence intrasexual competition and mateguarding behavior across a variety of species. Nevertheless, little is known about how perceived mate scarcity affects such behavior in humans. The purpose of this study was to examine the effects of experimentally induced perceptions of mate availability upon intrasexual competition, jealousy and aggressive mate guarding behavior. Heterosexual undergraduate students (N = 124, 60 women, 64 men) were primed with perceptions of either mate scarcity or mate abundance and subsequently completed measures of intrasexually competitive attitude, jealousy and willingness to aggress against a mate-poacher (either directly or indirectly). For both men and women, results showed that individuals who were exposed to the mate scarcity condition reported significantly more intrasexual competition, jealousy and willingness to aggress indirectly against a matepoacher compared to those exposed to the mate abundance condition. Results provide evidence of an attitudinal and behavioral shift toward sexual conflict when individuals perceive mates to be a scarce resource.