Males in many non-monogamous species have larger ranges than females do, a sex difference that has been well documented for decades and seems to be an aspect of male mating competition. Until recently, parallel data for humans have been mostly anecdotal and qualitative, but this is now changing as human behavioral ecologists turn their attention to matters of individual mobility. Sex differences in spatial cognition were among the first accepted psychological sex differences and, like differences in ranging behavior, are documented (...) for a growing set of species. This special issue is dedicated to exploring the possible adaptive links between these cognitive and ranging traits. Multiple hypotheses, at various levels of analysis, are considered. At the functional (ultimate) level, a mating-competition hypothesis suggests that range expansion may augment mating opportunities, and a fertility-and-parental-care hypothesis suggests that range contraction may facilitate offspring provisioning. At a more mechanistic (proximate) level, differences in cue availability may support or inhibit particular sex-specific navigation strategies, and spatial anxiety may usefully inhibit travel that would not justify its costs. Studies in four different cultures—Twe, Tsimane, Yucatec Maya, and Faroese—as well as an experimental study using virtual reality tools are the venue for testing these hypotheses. Our hope is to stimulate more research on the evolutionary and developmental processes responsible for this suite of linked behavioral and cognitive traits. (shrink)

Cross-cultural sex differences in mobility and harm avoidance have been widely reported, often emphasizing fitness benefits of long-distance travel for males and high costs for females. Data emerging from adults in small-scale societies, however, are challenging the assumption that female mobility is restricted during reproduction. Such findings warrant further exploration of the ontogeny of mobility. Here, using a combination of machine-learning, mixed-effects linear regression, and GIS mapping, we analyze range size, daily distance traveled, and harm avoidance among Hadza foragers during (...) middle childhood and adolescence. Distance traveled increased with age and, while male adolescents had the longest daily ranges, average daily distance traveled by each sex was similar. We found few age- or sex-related patterns in harm-avoidant responses and a high degree of individual variation. When queried on the same issues, children and their parents were often in alignment as to expectations pertaining to harm avoidance, and siblings tended to behave in similar ways. To the extent that sex differences in mobility did emerge, they were associated with ecological differences in physical threats associated with sex-specific foraging behaviors. Further, we found no strong association between harm avoidance and mobility. Young Hadza foragers of both sexes are highly mobile, regardless of how harm avoidant they are. Taken together, our findings indicate that the causal arrows between harm avoidance and mobility must be evaluated in ecologically specific frameworks where cultural expectations of juvenile mobility can be contextualized. (shrink)

To our knowledge, this is one of the first studies to test different theoretical models of working memory in childhood based on a computerized assessment. We tested this across several countries: Argentina, Brazil, Canada, Italy, and UK. The present study addressed the wider macro-cultural context and how this impacts working memory. We used two economic indices to characterize the participating countries and ranked the countries based on the Global Index of Cognitive Skills and Educational Attainment. Children between 5 and 10 (...) years completed the same set of short-term and working memory tests. There were two main findings. First, there was a similar pattern in verbal working memory across countries, which suggests that this skill may be relatively consistent across different cultural groups. In contrast, the pattern for visuo-spatial working memory was different across countries, which may explained by cultural differences and educational rankings of the countries. The second main finding was that both a domain-general model and a domain-specific model provided a reasonably good fit with the data, there was the high relationship between the verbal and visuo-spatial working memory constructs across the countries in the latter model. Thus, it may be a more parsimonious choice to rely on a three-factor model. The data also suggest culture-similar patterns in a computerized assessment of working memory. (shrink)

Venturing into novel terrain poses physical risks to a female and her offspring. Females have a greater tendency to avoid physical harm, while males tend to have larger range sizes and often outperform females in navigation-related tasks. Given this backdrop, we expected that females would explore a novel environment with more caution than males, and that more-cautious exploration would negatively affect navigation performance. Participants explored a novel, large-scale, virtual environment in search of five objects, pointed in the direction of each (...) object from the origin, and then navigated back to the objects. We found that females demonstrated more caution while exploring as reflected in the increased amounts of pausing and revisiting of previously traversed locations. In addition, more pausing and revisiting behaviors led to degradation in navigation performance. Finally, individual levels of trait harm avoidance were positively associated with the amount of revisiting behavior during exploration. These findings support the idea that the fitness costs associated with long-distance travel may encourage females to take a more cautious approach to spatial exploration, and that this caution may partially explain the sex differences in navigation performance. (shrink)

According to the evolutionary hypothesis of Silverman and Eals (1992, Sex differences in spatial abilities: Evolutionary theory and data. In J. H. Barkow, L. Cosmides, & J. Tooby (Eds.), The adapted mind: Evolutionary psychology and the generation of culture (pp. 533–549). Oxford: Oxford University Press), women evolutionary hypothesis, women surpass men in object location memory as a result of a sexual division in foraging activities among early humans. After surveying the main anthropological information on ancestral sex-related foraging, we review the (...) evidence on how robust women’s advantage in object location memory is. This leads us to suggest that the functional understanding of this type of memory would benefit from comparing men and women in carefully designed and ecologically meaningful cognitive contexts involving, for instance, incidental versus intentional settings that call for either the absolute or relative encoding of the locations of common versus uncommon objects. (shrink)