Baboons, bonds, biology, and lessons about early life adversity

Abstract

Adverse childhood experiences (ACEs) have been defined as those that exhibit a dose–response relationship with health risk behaviors and chronic diseases known to increase mortality (1). ACEs are also associated with biomarkers related to inflammation, genetics, and endocrine functioning (e.g., cortisol) (2). The standard compendium of 10 ACEs includes abuse (physical, emotional, sexual), neglect (physical, emotional), and household dysfunction (mental illness, mother treated violently, divorce, incarcerated relative, substance abuse). ACEs are, unfortunately, an all-too-prevalent reality in the US population. In 2017 to 2018, about 33% of children aged 0 to 17 had experienced at least one ACE, and 14% had experienced two or more (3). The question that now occupies many researchers in this field is, “How do events that happen in childhood persist to affect adult physical and mental health?” Data that address life course questions such as this are rarely available in studies of humans. In PNAS, Rosenbaum et al. (4) take advantage of a rich longitudinal data resource in their long-standing field study of female savannah baboons to test the plausibility of a well-reasoned hypothesis: Early life adversity is associated with increased fecal glucocorticoid (fGC) concentrations in adulthood, and this effect is mediated by social bond strength in adulthood (Fig. 1 A ). Fig. 1. Pathways linking early life adversity to adult fecal glucocorticoid (fGC) concentrations. Gray font and dashed arrows depict how childhood social bond strength could enter into explanations for adult fGC concentrations. ( A ) Mediation model: Adult social bond strength mediates the association between early life adversity and adult fGC concentrations. ( B ) Moderation model: Adult social bond strength moderates the association between early life adversity and adult fGC concentrations. ( C ) Independent effects model: Early life adversity and adult bond strength are independently associated with adult fGC concentrations. ( a ) Long-term (persistent) effects of childhood social bonds on adult fGC … [↵][1]1To whom correspondence may be addressed. Email: hawkley-louise{at}norc.org. [1]: #xref-corresp-1-1