Low Socioeconomic Status but Resilient: Panacea or Double Trouble? John Henryism in the International IMIAS Study of Older Adults.

John Henry (JH) theory provides a framework for understanding the physiological toll exerted on low socioeconomic status (SES) individuals as they overcome psychosocial stressors imposed by their environments. This theory suggests that resilience, a seemingly positive social adaptation, may in fact be physically deleterious. JH theory has been well-described in low-SES rural male African Americans, however it is currently unclear whether validity of this theory extends to women, other races and outside the rural US. We assessed whether, in individuals with low income, there is an association between self-mastery/resilience and either blood pressure or depressive symptoms that is different from the association seen in individuals with higher income. Data were obtained from 1353 older men and women participants of the International Mobility in Aging Study (IMIAS). Across 3 countries and 4 sites, higher self-mastery/resilience was associated with lower depressive symptoms in both low and high income groups. In low income individuals from Saint-Hyacinthe, Québec, higher self-mastery/resilience was associated with both higher mean systolic blood pressure (n = 240, β = 0.135, p ≤ 0.05) and higher mean diastolic blood pressure (n = 240, β = 0.241, p ≤ 0.0001). In the high income group of Saint-Hyacinthe, no such associations were observed. The findings in the Saint-Hyacinthe cohort (but not the other settings), are consistent with the John Henry hypothesis, and demonstrates this effect extends beyond a rural African American population. This finding indicates that in certain populations, the positive psychological effects of resilience come with a cost to physical health.