Examining Racial Disparities in Cognitive Ability over Time Among Older U.S. Adults: Does Stress Play a Role?

Objective: Racial differences in cognitive functioning have been widely documented. Further, a growing body of research suggests that stress is associated with poorer cognitive functioning, particularly among older adults.  Yet, few studies have specifically considered the possible influence of stressful life events and discrimination on cognitive ability and whether the effect of these stressors differs by race. This study longitudinally examines disparities in cognitive ability among older U.S. black and white adults.

Methods: Participants consisted of aging black and white adults enrolled in the Americans' Changing Lives study (ACL; N =3,617). Data were drawn from waves 4 and 5, which are 10 years apart. Cognitive impairment was assessed at both waves such that change in cognitive status was examined over time, and cognitive status as well as predictor and demographic variables were controlled at wave 4.

Results: Whereas there was no main effect of stressful life events or discrimination on cognition, there was a significant race effect, β = -.195, p = .013, such that whites have significantly lower wave 5 cognitive impairment scores compared to blacks, adjusting for demographics and depressive symptoms.  Inconsistent with predictions, there was no significant interaction between stressful events, discrimination and race, β = -.004, p = .950 and β = -.004, p = .908, respectively.

Conclusions: Race, rather than social stressors, appears to influence cognitive ability among aging adults.  In particular, blacks experience greater rates of cognitive decline over time compared to whites.  This finding highlights the importance of addressing racial disparities in cognition.