Previous research addressing the association between leisure and happiness has given rise to the hypothesis that informal social activities might contribute more to happiness than solitary activities. In the current study, we tested how the two types of leisure—social and solitary—contribute to a person’s subjective sense of well-being. For the empirical estimate, we used four consecutive quarters of data collected from 533 people over the age of 16, from 13 Tsimane’ hunter-farmer villages in the Bolivian Amazon. Results suggest that (...) only social, not solitary, leisure has a positive and statistically significant association with subjective well-being. The association between solitary leisure and subjective well-being was negligible or negative. Future research should focus on emic definitions of social and solitary time, for solitary time might not always be equivalent to leisure and productive group activities might substitute for social leisure. (shrink)

Children may be viewed as public goods whereby both parents receive equal genetic benefits yet one parent often invests more heavily than the other. We introduce a microeconomic framework for understanding household investment decisions to address questions concerning conflicts of interest over types and amount of work effort among married men and women. Although gains and costs of marriage may not be spread equally among marriage partners, marriage is still a favorable, efficient outcome under a wide range of conditions. This (...) bioeconomic framework subsumes both cooperative and conflictive views on the sexual division of labor. We test hypotheses concerning marriage markets, assortative mating, and men’s labor motivations among Tsimane forager-horticulturalists of Bolivia and find that: (1) men and women both value work effort in marital partners, (2) marital labor contributions are complementary, (3) work effort is correlated between spouses, (4) total production is correlated with total reproduction, and (5) better hunters have higher fitness gains within marital unions. (shrink)

Growing evidence suggests mothers invest more in girls than boys and fathers more in boys than girls. We develop a hypothesis that predicts preference for girls by the parent facing more resource constraints and preference for boys by the parent facing less constraint. We test the hypothesis with panel data from the Tsimane’, a foraging-farming society in the Bolivian Amazon. Tsimane’ mothers face more resource constraints than fathers. As predicted, mother’s wealth protected girl’s BMI, but father’s wealth had (...) weak effects on boy’s BMI. Numerous tests yielded robust results, including those that controlled for fixed effects of child and household. (shrink)

This paper examines social determinants of resource competition among Tsimane Amerindian women of Bolivia. We introduce a semi-anonymous experiment (the Social Strategy Game) designed to simulate resource competition among women. Information concerning dyadic social relationships and demographic data were collected to identify variables influencing resource competition intensity, as measured by the number of beads one woman took from another. Relationship variables are used to test how the affiliative or competitive aspects of dyads affect the extent of prosociality in the (...) game. Using a mixed-modeling procedure, we find that women compete with those with whom they are quarreling over accusations of meat theft, mate competition, and rumor spreading. They also compete with members of their social network and with those who were designated as cooperative helpers or as close kin. Women take fewer beads from desired friends, neighbors, and from those viewed as enemies. We interpret favoritism toward enemies as resulting from fear of retribution. Our results suggest that social relations among women are multifaceted and often cannot be simplified by exclusive focus on genetic relatedness, physical proximity, or reciprocity. We argue that a complex understanding of cooperation and competition among women may require important contextual information concerning relationship history in addition to typical features of resource ecology. (shrink)

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)

We examine the opportunities children have for interacting with others and the extent to which they are the focus of others’ visual attention in five societies where extended family communities are the norm. We compiled six video-recorded datasets collected by a team of anthropologists and psychologists conducting long-term research in each society. The six datasets include video observations of children among the Yasawas, Tanna, Tsimane, Huatasani, and Aka. Each dataset consists of a series of videos of children ranging in (...) age from 2 months to 12 years in their everyday contexts. We coded 998 videos and identified with whom children had opportunities to interact as well as the number of individuals and the proportion of observed time that children spent with these individuals. We also examined the proportion of time children received direct visual gaze. Our results indicate that children less than 5 years old spend the majority of their observed time in the presence of one female adult. This is the case across the five societies. In the three societies from which we have older children, we find a clear shift around 5 years of age, with children spending the majority of their time with other children. We also coded the presence or absence of a primary caregiver and found that caregivers remained within 2 ft of target children until 7 years of age. When they were in the company of a primary caregiver, children older than seven spent the majority of their time more than 2 ft from the caregiver. We found a consistent trend across societies with decreasing focal attention on the child with increasing child age. These findings show remarkable consistency across these societies in children’s interaction opportunities and that a developmental approach is needed to fully understand human development because the social context is dynamic across the lifespan. These data can serve as a springboard for future research examining social development in everyday contexts. (shrink)

In small-scale societies, punishment of adults is infrequent and employed when the anticipated cost-to-benefit ratio is low, such as when punishment is collectively justified and administered. In addition, benefits may exceed costs when punishers have relatively greater physical and social capital and gain more from cooperation. We provide examples from the Tsimane horticulturalists of Bolivia to support our claims.

Certain social context features (e.g., maternal presence) are known to increase young children's exploration, a key process by which they learn. Yet limited research investigates the role of social context, especially peer presence, in exploration across development. We investigate whether the effect of peer presence on exploration is mediated by age or cultural‐specific experiences. We test its impact on exploration across development (2–11 years) and across cultures (United States and the Tsimane', indigenous farmer‐foragers in Bolivia). Specifically, peer presence does (...) not boost exploration among young U.S. children and becomes more inhibitory among school‐age children. In contrast, peer presence facilitates exploration and provides an additional boost for older Tsimane' children, who differ from U.S. children in their cultural‐specific learning experiences (e.g., formal education), among other differences. We discuss potential cultural factors and mechanisms by which peer presence may boost exploratory behavior. (shrink)

Navigational performance responds to navigational challenges, and both decline with age in Western populations as older people become less mobile. But mobility does not decline everywhere; Tsimané forager-farmers in Bolivia remain highly mobile throughout adulthood, traveling frequently by foot and dugout canoe for subsistence and social visitation. We, therefore, measured both natural mobility and navigational performance in 305 Tsimané adults, to assess differences with age and to test whether greater mobility was related to better navigational performance across the lifespan. Daily (...) mobility was measured by GPS tracking, regional mobility through interview, navigational performance through pointing accuracy and perspective taking in environmental space, and mental rotation by a computerized task. Although mental rotation and spatial perspective taking declined with age, mobility and pointing accuracy remained high from mid-life through old age. Greater regional mobility was associated with greater accuracy at pointing and perspective taking, suggesting that spatial experience at environmental scales may help maintain navigational performance in later adulthood. (shrink)

Navigational performance responds to navigational challenges, and both decline with age in Western populations as older people become less mobile. But mobility does not decline everywhere; Tsimané forager-farmers in Bolivia remain highly mobile throughout adulthood, traveling frequently by foot and dugout canoe for subsistence and social visitation. We, therefore, measured both natural mobility and navigational performance in 305 Tsimané adults, to assess differences with age and to test whether greater mobility was related to better navigational performance across the lifespan. Daily (...) mobility was measured by GPS tracking, regional mobility through interview, navigational performance through pointing accuracy and perspective taking in environmental space, and mental rotation by a computerized task. Although mental rotation and spatial perspective taking declined with age, mobility and pointing accuracy remained high from mid-life through old age. Greater regional mobility was associated with greater accuracy at pointing and perspective taking, suggesting that spatial experience at environmental scales may help maintain navigational performance in later adulthood. (shrink)

Although subsistence hunting is cross-culturally an activity led and practiced mostly by men, a rich body of literature shows that in many small-scale societies women also engage in hunting in varied and often inconspicuous ways. Using data collected among two contemporary forager-horticulturalist societies facing rapid change, we compare the technological and social characteristics of hunting trips led by women and men and analyze the specific socioeconomic characteristics that facilitate or constrain women’s engagement in hunting. Results from interviews on daily activities (...) with 121 Tsimane’ and 159 Baka show that Tsimane’ and Baka women participate in subsistence hunting, albeit using different techniques and in different social contexts than men. We also found differences in the individual and household socioeconomic profiles of Tsimane’ and Baka women who hunt and those who do not hunt. Moreover, the characteristics that differentiate hunter and non-hunter women vary from one society to the other, suggesting that gender roles in relation to hunting are fluid and likely to change, not only across societies, but also as societies change. (shrink)