Multiple stressors affect developing and adult organisms, thereby partly structuring their phenotypes. Determining how stressors influence health, well-being, and longevity in human and nonhuman primate populations are major foci within biological anthropology. Although much effort has been devoted to examining responses to multiple environmental and sociocultural stressors, no holistic metric to measure stress-related physiological dysfunction has been widely applied within biological anthropology. Researchers from disciplines outside anthropology are using allostatic load indices (ALIs) to estimate such dysregulation and examine life-long outcomes of stressor exposures, including morbidity and mortality. Following allostasis theory, allostatic load represents accumulated physiological and somatic damage secondary to stressors and senescent processes experienced over the lifespan. ALIs estimate this wear-and-tear using a composite of biomarkers representing neuroendocrine, cardiovascular, metabolic, and immune systems. Across samples, ALIs are associated significantly with multiple individual characteristics (e.g., age, sex, education, DNA variation) of interest within biological anthropology. They also predict future outcomes, including aspects of life history variation (e.g., survival, lifespan), mental and physical health, morbidity and mortality, and likely health disparities between groups, by stressor exposures, ethnicity, occupations, and degree of departure from local indigenous life ways and integration into external and commodified ones. ALIs also may be applied to similar stress-related research areas among nonhuman primates. Given the reports from multiple research endeavors, here we propose ALIs may be useful for assessing stressors, stress responses, and stress-related dysfunction, current and long-term cognitive function, health and well-being, and risk of early mortality across many research programs within biological anthropology.
K E Y W O R D Saging, allostasis, frailty, growth and development, nonhuman primates, senescence, stress
| I N T R O D U C T I O NTraditional research foci within biological anthropology include variations in stress, morbidity, and mortality (for reviews, see Ice & James, 2007;Little, 2010). Despite this long-term focus, the field continues to pursue a reliable, relatively easy to apply metric for assessing lifetime stress and stress-related outcomes. We suggest incorporating the theory of allostasis and methods for assessing allostatic load within anthropological theory and methodology to aid in closing this gap. As a theory, allostasis was developed to explain how mammalian physiological responses to stressors in their environments evolved to maximize the probability of survival while limiting somatic damage (Korte, Koolhaas, Wingfield, & McEwen, 2005;McEwen & Stellar, 1993;McEwen & Wingfield, 2003;Sterling, 2004Sterling, , 2012Sterling & Eyer, 1988). Unfortunately, such beneficial defensive responses come at a cost and, over time, repeated allostatic activi...