The Moderating Effect of Chronological Age on the Relation Between Neuroticism and Physical Functioning: Cross-Sectional Evidence From Two French Samples.

Objectives. Prior studies of age-restricted samples have demonstrated that, in older adulthood, neuroticism is negatively associated with difficulties performing specific daily activities. No studies of neuroticism and physical functioning have been conducted on life-span samples. This study tested the hypothesis that the relationship between neuroticism and physical functioning is stronger in older people compared with younger and middle-aged adults. Method. Data were obtained from 2 independent French samples (n = 1,132 and 1,661 for Samples 1 and 2, respectively) ranging in age from 18 to 97. In addition to reporting sociodemographics, participants completed the Big Five Inventory, the physical functioning scale of the 36-Item Short Form Health Survey, and measures of disease burden. Results. In both samples, regression analysis indicated that neuroticism is more negatively associated with physical functioning with advancing age, controlling for gender, marital status, disease burden, and educational attainment. Discussion. In life-span samples of more than 2,700 adults, neuroticism was more strongly associated with worse physical functioning among older people compared with younger and middle-aged adults. Longitudinal research is needed to confirm this finding and to identify potential mediators.