RESUMO
Intergroup and long-distance relationships are both central features of human social life, but because intergroup relationships are emphasized in the literature, long-distance relationships are often overlooked. Here, we make the case that intergroup and long-distance relationships should be studied as distinct, albeit related, features of human sociality. First, we review the functions of both kinds of relationship: while both can be conduits for difficult-to-access resources, intergroup relationships can reduce intergroup conflict whereas long-distance relationships are especially effective at buffering widespread resource shortfalls. Second, to illustrate the importance of distinguishing the two relationship types, we present a case study from rural Bolivia. Combining ethnography and two different experimental techniques, we find that the importance of intergroup relationships-and the salience of group membership itself-varies across populations and across methods. Although ethnography revealed that participants often rely on long-distance relationships for resource access, we were unable to capture participant preferences for these relationships with a forced-choice technique. Taken together, our review and empirical data highlight that (1) intergroup and long-distance relationships can have different functions and can be more or less important in different contexts and (2) validating experimental field data with ethnography is crucial for work on human sociality. We close by outlining future directions for research on long-distance relationships in humans.
Assuntos
Relações Interpessoais , Comportamento Social , Humanos , BolíviaRESUMO
OBJECTIVES: Long-distance social relationships have been a feature of human evolutionary history; evidence from the paleoanthropological, archeological, and ethnographic records suggest that one function of these relationships is to manage the risk of resource shortfalls due to climate variability. We should expect long-distance relationships to be especially important when shortfalls are chronic or temporally positively autocorrelated, as these are more likely to exhaust local adaptations for managing risk. Further, individuals who experience shortfalls not as rare shocks, but as patterned events, should be more likely to pay the costs of maintaining long-distance relationships. We test these hypotheses in the context of two communities of Bolivian horticulturalists, where climate variability-especially precipitation variability-is relevant to production and access to long-distance connections is improving. METHODS: Data on individuals' migration histories, social relationships, and other relevant variables were collected in 2017 (n = 119). Precipitation data were obtained from the US National Center for Atmospheric Research, allowing us to estimate participants' exposure to drought and excess precipitation. RESULTS: Exposure duration, proximity in time, and frequency did not predict having a greater number of long-distance relationships. Males, extraverted individuals, and those who had traveled more did have more long-distance relationships, however. CONCLUSION: Another function of long-distance relationships is to access resources that can never be obtained locally; ethnographic data suggest this is their primary function in rural Bolivia. We conclude by refining our predictions about the conditions under which long-distance relationships are likely to help individuals manage the risks posed by climate variability.
Assuntos
Clima , Características da Família , Medição de Risco , Bolívia , Feminino , Humanos , Masculino , RiscoRESUMO
OBJECTIVES: This study explores whether cardiovascular fitness levels and senescent decline are similar in the Tsimane of Bolivia and Canadians, as well as other subsistence and industrialized populations. Among Tsimane, we examine whether morbidity predicts lower levels and faster decline of cardiovascular fitness, or whether their lifestyle (e.g., high physical activity) promotes high levels and slow decline. Alternatively, high activity levels and morbidity might counterbalance such that Tsimane fitness levels and decline are similar to those in industrialized populations. METHODS: Maximal oxygen uptake (VO2 max) was estimated using a step test heart rate method for 701 participants. We compared these estimates to the Canadian Health Measures Survey and previous studies in industrialized and subsistence populations. We evaluated whether health indicators and proxies for market integration were associated with VO2 max levels and rate of decline for the Tsimane. RESULTS: The Tsimane have significantly higher levels of VO2 max and slower rates of decline than Canadians; initial evidence suggests differences in VO2 max levels between other subsistence and industrialized populations. Low hemoglobin predicts low VO2 max for Tsimane women while helminth infection predicts high VO2 max for Tsimane men, though results might be specific to the VO2 max scaling parameter used. No variables tested interact with age to moderate decline. CONCLUSIONS: The Tsimane demonstrate higher levels of cardiovascular fitness than industrialized populations, but levels similar to other subsistence populations. The high VO2 max of Tsimane is consistent with their high physical activity and few indicators of cardiovascular disease, measured in previous studies.