Suchergebnisse

The conditions that propel humans to make sacrifices for groups of unrelated, and often unknown, individualshas received considerable attention across scientific disciplines. Evolutionary explanations for this type of sa-crifice have focused on how men form strategic coalitions organized around kin networks and reciprocity whenfaced with out-group threats. Few studies, however, have analyzed how women respond to external threats.Using data from one of the largest female paramilitary organizations in history we show that women who havemore brothers, women whose husbands serve in the military and women without children are more likely tovolunteer. These results provide qualified support for the hypothesis that women are more likely to sacrifice fortheir country when members of their family are at risk. Overall, our analysis suggests that self-sacrifice andintense bonding with an imagined community of unknown individuals, such as the nation state, may arise out ofa suite of psychological adaptations designed to facilitate cooperation among kin (i.e. kin psychology). Theseresults can be interpreted within the framework of kin selection showing how individuals come to view un-related group members as family. They may also shed light on various theories of group alignment, such as'identity fusion'–whereby individuals align their personal identity and interests with those of the group–and onour understanding of evolutionary adaptations that cause women to direct altruism toward in-groups. ; Peer reviewed

AbstractDispersal does not only mean moving from one environment to another, but can also refer to shifting from one social group to another. Individual characteristics such as sex, age and family structure might influence an individual's propensity to disperse. In this study, we use a unique dataset of an evacuated World War II Finnish population, to test how sex, age, number of siblings and birth order influence an individual's dispersal away from their own social group at a time when society was rapidly changing. We found that young women dispersed more than young men, but the difference decreased with age. This suggests that young men might benefit more from staying near a familiar social group, whereas young women could benefit more from moving elsewhere to find work or spouses. We also found that having more younger brothers increased the propensity for firstborns to disperse more than for laterborns, indicating that younger brothers might pressure firstborn individuals into leaving. However, sisters did not have the same effect as brothers. Overall, the results show that individual characteristics are important in understanding dispersal behaviour, but environmental properties such as social structure and the period of flux after World War II might upend the standard predictions concerning residence and dispersal.Social media summary:Individual characteristics influence dispersal away from social group after a forced migration in a Finnish population

Understanding how refugees integrate into host societies has broad implications for researchers interested in intergroup conflict and for governments concerned with promoting social cohesion. Using detailed records tracking the movements and life histories of Finnish evacuees during World War II, we find that evacuees who intermarry are more likely to be educated, work in professional occupations, marry someone higher in social status and remain in the host community. Evacuees who intermarry before the war have fewer children, whereas those who marry into their host community after the war have more children. These results indicate that life-history and assimilation outcomes depend on key differences between pre-war environments—when migrants are living in their own communities—and post-war environments—when migrants are living in the host community. Overall, this suggests that integration involves a trade-off between reproduction and status such that evacuees who integrate gain social status, whereas those who maintain stronger bonds with their natal communities have higher fertility. We discuss these results within the framework of social capital, intergroup conflict and life-history theory and suggest how they can inform our understanding of evolutionary adaptations that affect tribalism. ; Peer reviewed