Socioeconomic Differences in the Association Between the Big Five Personality Traits and Episodic Memory Trajectories...

Episodic memory trajectories vary substantially between individuals in the second half of life: some maintain high levels of performance into their 80s, whereas others experience marked declines as early as their 50s. Identifying factors that help explain this heterogeneity is critical for understanding cognitive aging. Drawing on the resource substitution hypothesis and the Openness-Fluid-Crystallized-Intelligence (OFCI) model, this preregistered study examined whether the Big Five personality traits and their interactions with socioeconomic status (SES) predict individual differences in episodic memory trajectories, testing also potential non-linear associations. We expected higher openness and lower neuroticism to be associated with better memory levels and slower decline, with stronger effects at lower levels of SES.

We analyzed data from 57,947 individuals aged 50 and older (M = 67.78, SD = 9.03) who participated in at least two waves (7, 8, or 9) of the Survey of Health, Ageing, and Retirement in Europe (SHARE). Multilevel growth models were used to estimate associations between personality and episodic memory levels and 5-year change, and whether SES (i.e., education, income, and wealth) moderated these associations.

Consistent with the OFCI model and the resource substitution hypothesis, higher openness was associated with better episodic memory levels, particularly among individuals with lower wealth. Higher neuroticism and lower conscientiousness were linked to poorer episodic memory levels, but only among less wealthy individuals. Higher extraversion was associated with better memory levels overall, and individuals at the extremes of extraversion exhibited somewhat flatter declines compared to those with moderate levels. Except for extraversion, there was little evidence for non-linear associations or for associations with 5-year change in episodic memory.

Our findings underscore the relevance of wealth as an important socioeconomic resource for cognitive health beyond income and education, particularly in old age, when income is typically reduced. Overall, the results support modest concurrent associations between personality, SES, and episodic memory levels, but provide hardly any evidence for longitudinal effects. More frequent and longer-term longitudinal assessments are needed to clarify potential effects on cognitive aging.