Converging Views on Health Effects in Social Species

Social determinants of health are not just a concern for humans. Many social species legibly register the negative impacts of isolation and stress, as well as the positive effects of tight social integration. The case for thinking about these impacts in parallel, between humans and nonhumans, is developed in a review article in Science, “Social determinants of health and survival in humans and other animals.” This is a subject that opens or extends many lines of inquiry concerning how to analyze sociality across species, and how to think anew about making the case that social inequalities are devastating for humans’ health.

The authors review evidence indicating “that social impacts on life span are a shared phenomenon across humans and other social mammals and that the health-related outcomes of social adversity in nonhuman animals parallel socially patterned pathologies in humans.” Effects of social environments in other orders—birds and eusocial insects—are also becoming more apparent, but the authors leave those taxa aside for the now. Their focus is on the converging research on the consequences of social adversity on life spans across a broad spectrum of social environments. That is, this review highlights the generative intellectual exchange being realized by thinking about what constitutes these parallels, as much as it is concerned with aligning the range of studies and findings across social mammals.

This convergence rests, not surprisingly, upon the far longer tradition of studying social determinants in the social sciences. But the authors argue that what this newly makes possible is the capacity to frame these determinants in terms of causation, not just correlations. They review a range of experimental limits to proving the “social causation” hypothesis with humans, both due to complexity of health circumstances and the ethical, political constraints on human experimentation: “experimental studies of exposure to many sources of social adversity are nearly impossible in humans. The problem is further compounded by the absence of information about social and biological conditions before the start of many key studies and by the interdependence between social gradients and health over time. Longitudinal datasets that include baseline measures partially address these challenges but still cannot unambiguously disentangle causal pathways because of the difficulty of excluding the effects of correlated or confounding variables (such as time-varying confounders).”

Another challenge they reference is that “social adversity is linked to a remarkably broad set of conditions, including diseases as distinct as tuberculosis, diabetes, cardiovascular disease, and cancer. The fact that so many different physiological systems are socially patterned makes choosing an appropriate animal, tissue, or cellular model difficult. This problem is further complicated by the fact that studies of the social environment minimally require social interaction in groups or communities, meaning that social cues cannot be readily modeled in individually housed organisms or cell lines.” But the promise lies in the potential to align “social adversity” with “classical host-agent-environment models,” which may be realized experimentally with a variety of model organisms. The ability to demonstrate biological pathways for social adversity to impact health across a broad range of social mammals should help to make the case of its operation among humans, as well.

Leaving aside these important possibilities, I’ll focus on the core intellectual development highlighted in this review: “Over the past decade, the historically distinct agendas of social science and evolutionary biology have begun to converge. In particular, several long-term studies in wild social mammals now contain enough data to support full life course analyses and have revealed unexpectedly strong links between the social environment and mortality risk that parallel those from long-term studies in humans.” The authors acknowledge important differences in disciplinary orientations: social scientists direct their work toward policy changes that will mitigate these deleterious health effects, while evolutionary biologists are focused on answering questions about the origins of sociality and its consequences for reproductive fitness. And this latter subject will certainly make many social scientists squeamish about the host of possible misinterpretations of evolutionary dynamics in relation to modern humans, based on a well-documented history of such instances. But the exciting point, say, for multispecies research in the humanities is the means to “place observation in humans on a biological continuum with other species.” Rather than regarding nonhumans as wholly Other and fundamentally unknowable, parallel findings on the social determinants of health suggest a variety of ways to calibrate research on nonhumans with the wealth of knowledge on social dynamics among humans.

This leads to my main point. The efforts to study nonhuman “social environments” highlighted in this review align with ethologist Frans De Waal’s acknowledgement “that social challenges have been neglected for too long in discussions of cognitive evolution, which tend to focus on interactions with environment.” Environment-organism interactions dominate thinking about evolution, and that has left the “social” difficult for biologists both to model and analyze—until, that is, it’s appended to “environment,” as in this review article. So this convergence, if it is to be further realized and developed, needs to feature ways to combine “biological mechanisms” with “social dynamics” as studied by social scientists. The fundamental premise of social theory—referenced here as “the sociological literature for at least 120 years”—is that these dynamics are expressly not reducible to biological explanation.

To think these parallels, then, a more ample and robust understanding of sociality is going to be necessary, one that draws as much from social theory as from evolutionary theory. Here, too, there are tantalizing overlapping concepts, such as “emergence” or “complexity” and “self-organizing” dynamics—all versions of thinking non-reductively about social processes. Or, more simply, it can be advanced by transposing performance models of sociality onto nonhumans. Reading and responding to “social cues”—mentioned in this review—involve more than mechanistic “biological sensors,” as purported by evolutionary biologists. They require making sense of the relative position of an array of social selves. Social cues entail both assertions of identity within social hierarchies and an assessment of responses by group members, either acknowledging or contesting such performances. “Accurately assessing the ‘appropriate’ social response” is not just an experimental concern; it’s a challenge facing many social mammals and likely involves a good deal of social learning and the non-hereditary transmission of local “traditions.” As we are increasingly realizing, this reflects a variety of instances of culture in nonhumans. The surge of research on animal cultures needs to be part of this generative convergence.

That said, I find the collective, social mammalian “us” conjured in this review quite enticing: “these findings lay the groundwork for understanding how social adversity makes us vulnerable.”

Recommended Citation

Hartigan, John. “Converging Views on Health Effects in Social Species.” September 8, 2020. Commentary to Social Theory for Nonhumans. Manifold ed. Minneapolis: University of Minnesota Press, forthcoming. https://doi.org/10.5749/9781452958446.