The current study aimed to identify demographic, personality and substance-use characteristics associated with forming romantic relationships. Data were collected by two online surveys among students in Bergen, Norway, during the autumn of 2015 (T1) and by a follow-up survey that was conducted 12 months later (T2). The current sample consists of the 2404 participants who reported being single at T1 (mean age 23.2) and who participated in both waves of the survey. Binary logistic regression analyses were conducted. Separate analyses were conducted for both sexes and for the entire sample of participants. High extroversion scores predicted relationship formation. For women, having a child/children, higher scores on neuroticism, alcohol use and illegal substance use positively predicted relationship formation, while for men, age and openness were positive predictors. The study contributes with several novel findings. In general, characteristics related to a need for support predicted romantic relationship formation among women, while characteristics associated with increased resource acquisition potential predicted relationship formation among men. The general pattern of findings is in line with established evolutionary theories such as the sexual strategies theory and the parental investment theory.

Urban living is often thought to promote incivility, but the existing sociological evidence paints a mixed picture. We aimed to examine the urban incivility phenomenon from an evolutionist’s perspective. Small communities are expected to show a higher incidence of helping because the applicability of theories such as kin selection, direct reciprocity and indirect reciprocity to acts of cooperative behaviour is augmented in small-scale demographic settings. Smaller communities have a reduced total pool of individuals to interact with, increasing the likelihood of encountering any given individual multiple times. This makes it easier for individuals to form cooperative relationships with one another, which may facilitate prosociality within smaller communities. Using the lost letter technique, our results show that city dwelling, compared with rural residence, per se does not negatively influence prosociality. This contradicts the expected erosion of cooperative behaviour in anonymous cities and adds to our understanding of the interplay between human macroecology and individual behavioural tendencies.

Affiliative and pathogen-avoidant motives adaptively influence interpersonal preferences. For facial structures connoting extraversion, affiliative motives heighten preferences for extraverted faces, whereas pathogen-avoidant motives downregulate preferences. Despite what appears to be competing tension between motives for preferences in extraverted faces, previous research had yet to identify this possibility within a single experiment. The current study temporally activated an affiliative, pathogen-avoidant, or control state before tasking participants with indicating preferences for extraverted faces, relative to introverted, and support for campus-wide social networking activities to demonstrate convergence with previous findings demonstrating temporal shifts in affiliative interest. Although activated motivational states did not influence interpersonal preferences directly in this study, mediation analyses revealed participants’ upregulated extraverted face preferences and support for a campus social network following an exclusionary experience because of a heightened affiliative desire. We frame results as motivational tradeoffs, offering suggestions to identify competing motive effects more effectively for future research.

Shoulder to hip ratio (SHR) is a sexually dimorphic trait in humans, yet no previous study has investigated the gazing behavior and perceived physical attractiveness of men and women in relation to men and women’s SHRs. Men and women are attentive to men’s upper body and consider higher SHRs as cues to masculinity, strength, and formidability. Moreover, while women’s shoulder width varies from one individual to another, to our knowledge no previous study has investigated perceived attractiveness and eye movement in relation to women’s SHR. Therefore, in the current study, we investigated attractiveness ratings and eye movements of both men and women to front- and back-posed male and female stimuli varying in SHR. Our results showed that men prefer more masculine ratios for men and less masculine ratios for women. However, the results also showed that women preferred an intermediate SHR for both men and women in the back view while their preference in the front view is not influenced by SHR. Eye movements showed that men viewed the chest region of other men in the front and back views of stimuli, and they had longer dwell time on chests of male stimuli with higher SHRs, while no significant difference was found for dwell time on chests of female stimuli varying in SHR. Also, no differences were observed for female participants in dwell time, for either chest regions of SHRs of male stimuli or for the chests of female stimuli. Altogether, the results of this study suggest that men more than women are attentive to variations in SHRs.

Psychologists regularly draw inferences about populations based on data from small samples of people, and so have long been interested in how well those samples generalise to wider populations. There is a consensus that psychology probably relies too much on samples from Western, Educated, Industrialised, Rich and Democratic (WEIRD) societies and among those from university students. Online surveys might be used to increase sample diversity, although online sampling still reaches only a restricted range of participants. Studies from evolutionary psychology often seek to uncover aspects of evolved universal characteristics, and so might demonstrate a particular interest in the use of diverse samples. Here, we empirically examine the samples used in the 2015–2016 volumes of ‘Evolution & Human Behavior’ (104 articles) and ‘Evolutionary Psychology’ (76 articles). Our database consists of 311 samples of humans (median sample size = 186). The majority of samples were either online or student samples (70% of samples), followed by other adult Western samples (19%). Two hundred fifty-three (81%) of the samples were classified as ‘Western’ (Europe/North America/Australia). The remaining samples were predominantly from Asia (N = 37; 12%, mostly Japan). Only a small fraction of the samples were taken from Latin American and Caribbean (N = 8) or African (N = 6) countries. The median sample size did not differ significantly between continents, but online samples (both paid and unpaid) were typically larger than samples sourced offline. It seems that the samples used are more diverse than those that have been reported in reviews of the literature from social and developmental psychology, perhaps because evolutionary psychology has a greater inherent need to test hypotheses about an evolved and universal human nature. However, it is also apparent that the majority of samples within contemporary evolutionary psychology research remain WEIRD.

Short-term mating strategies involve casual sex, multiple partners, and short-time intervals before initiating intercourse. Such strategies should be difficult to implement in the presence of high levels of sexual disgust. Researchers have therefore suggested—and found evidence for—the hypothesis that individuals with a stronger proclivity for short-term mating have lower levels of sexual disgust. Here, we suggest a related hypothesis: inducing sexual disgust should reduce desire for short-term mating. Experiment 1 (N = 341) and experiment 2 (N = 361) investigated the effects of disgust induction on desire for short-term mating. Both studies found that inducing disgust reduces desire for short-term mating, and that the effect of sexual disgust is particularly strong. These results support the novel hypothesis advanced here and corroborate the broader hypothesis that reduced sexual disgust is a previously undiscovered design feature of short-term mating strategies.

The neuropsychological deciphering of religion suggests that the ability to believe in supernatural agents depends on cognitive mechanisms already present in our remote human ancestors. Current research has mainly focused on the cognitive accounts of religion, which do not satisfactorily explain religious motivation. Here, I defend the hypothesis that religious motivation recruits a motivational system that is not specifically human, and that underpins foraging activity under harsh environmental conditions. This motivational system, referred to as incentive hope, denotes motivational excitement for adversity avoidance (reward or relief) when difficulties (non-reward or punishment) are encountered. Incentive hope boosts foraging activity and therefore increases the probability of reward in a hostile environment, independent of any knowledge or awareness of what’s going on. It is shown how religious practices, which largely consist of adversity-avoidance strategies when adversity in life is high, could rely on incentive hope—revealed and enriched through self-awareness and introspection as hope in humans. Some original predictions to test this hypothesis are discussed.

In a trilogy of books, Kevin MacDonald argues that Judaism is a “group evolutionary strategy.” According to his theory, Jews are genetically and culturally adapted to advance their own group interests at the expense of gentiles. Several influential twentieth-century liberal intellectual and political movements were designed by Jews to promote separatism and group continuity among themselves while undermining gentile society. According to Cofnas [Human Nature, 29, 134–156, 2018], MacDonald’s argument is based on “misrepresented sources and cherry-picked facts.” Cofnas proposed the “default hypothesis” to explain Jewish overrepresentation among the leaders of liberal intellectual and political movements: Because of their relatively high IQ and concentration in influential urban areas, Jews are overrepresented in all (non-overtly anti-Semitic) cognitively demanding activities. Dutton [Evolutionary Psychological Science, 2018] objects to Cofnas, claiming that, “from the perspective of evolutionary psychology,” MacDonald’s theory is more “plausible” than the default hypothesis because “people tend to act in their ethnic interests” and Jews are particularly high in ethnocentrism. Contra Dutton, it is argued here that there is no evidence to support the general notion that people tend to act in their ethnic interests. The evidence suggests, if anything, that Jews are not particularly ethnocentric. There are no theoretical principles or established empirical findings of evolutionary psychology that make MacDonald’s theory “plausible.”

Few material goods entail as high a cost and carry as little practical value as an engagement ring. Despite their obvious signaling value, engagement ring expenditures have rarely been studied. The purpose of the current study was to experimentally manipulate a discrepancy in the physical attractiveness of romantic partners to determine its effect on hypothetical engagement ring purchases. We predicted that (1) men would purchase larger, more expensive engagement rings when imagining themselves mated to a more attractive rather than less attractive woman and (2) women would desire larger, more expensive engagement rings when imagining themselves mated to a less attractive rather than more attractive man. We further predicted a positive correlation between women’s self-ratings of attractiveness and the size and cost of the engagement ring women chose, regardless of target attractiveness. Results supported all three predictions. Data about the cost and quality of actual engagement rings was also collected to explore their correlations with age and attractiveness discrepancies in real-world couples; however, we failed to find a consistent pattern whereby more desirable women received more expensive and higher quality engagement rings. Results from the experimental portion of the current study show that men invest greater resources in attractive women and that increased resource investment can compensate for decreased physical attractiveness within the domain of women’s mate preferences.