Do people manage climate risk through long‐distance relationships?

Abstract

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. | INTRODUCTIONClimate change is one of the most pressing issues facing humans in the early 21st century. However, humans are no strangers to climate change: it has influenced hominin evolution, including the evolution of hominin social systems, since our last common ancestor with chimpanzees and bonobos (Pisor & Jones, 2021). Climate variability,

Contributions of evolutionary anthropology to understanding climate‐induced human migration

“…Work on mobility and behaviors such as maintaining extended social networks through visiting and exchange have long been of interest to evolutionary anthropologists (Wiessner, 1977 ). Pisor and Jones ( 2020a , 2020b ) examine the hypothesis that long distance relationships may be particularly important in coping with climate variability. They find little evidence for this function among Bolivian farmers, perhaps because climate variability impedes long‐distance travel, at least in the short term.…”

“…Two keys to understanding the human story—climate and migration—are central research themes in evolutionary anthropology, both the subject of decades of study. Prominent theories of human evolution, including of the evolution of bipedalism and increased brain size, have centered explicitly on environmental change and climate variability (reviewed in the introduction to this special issue, Pisor & Jones, 2020a ; Pisor & Jones, 2020b ). Migration also plays an integral role in understanding population structure and gene flow (Crawford & Campbell, 2012 ; Fix, 1999 ), and genetic research has been coupled with evidence from linguistics and archaeology to retrace the historical migration routes of humans globally (see Renfrew, 2010 ).…”

“…Evolutionary anthropologists, however, are conspicuously lacking from this impressive edited volume. It is also to these other social sciences that policymakers have turned most in trying to better understand climate and migration (Pisor & Jones, 2020a ; Pisor & Jones, 2020b ). Results include policy reports by groups such as the International Organization of Migration that consider the impact of environmental change on migration (McAdam & Limon, 2015 ; United Nations, 2019 ).…”

“…In HBE and evolutionary archaeology, mobility studies ask questions about human movement at all spatial scales, from foraging distances (e.g., Bliege Bird & Bird, 2020 ; Wood et al, 2021 ), to visiting friends and family in neighboring communities (e.g., Pisor & Jones, 2020a ; Pisor & Jones, 2020b ), to crossing seas to colonize unoccupied islands (e.g., Giovas & Fitzpatrick, 2014 ). The behavior typified by this last example is also termed migration or dispersal , where the movement is associated with switching one's place of habitual residence from one location to another.…”

How can evolutionary and biological anthropologists engage broader audiences?

“…We have the tools, experience, and perspectives to understand the diverse range of human-environment interactions, past and present, and to unify scattered empirical observations about human biology and behavior from across disciplines, often under approaches like Indigenous studies or political economy (Gibson & Lawson, 2015;Jones, 2009;Smith, 2013). We can bring diversity to conversations about policy and human nature by injecting data from contemporary peoples whose perspectives are often absent (Bliege Bird & Bird, 2021;Broesch et al, 2020;Hazel et al, 2021;Kramer & Hackman, 2021;Pisor & Jones, 2021b;Ready & Collings, 2021), as well as past peoples whose experiences are instructive but often forgotten (Douglass & Rasolondrainy, 2021;Kohler & Rockman, 2020). Given that the story of human evolution is one of adaptation to changing climates (Behrensmeyer, 2006), EBAs are exceedingly well-positioned to contribute to debates about current and future adaptation to climate change (Pisor & Jones, 2021a)-and contribute we should, now, as climate change threatens to displace 2-4 billion people in the next 50 years (Xu et al, 2020).…”