Ten Years of Actor and Cross-Partner Influence on Cognitive Function: Between- and Within-Couple Analysis

Although cognitive interdependence among spouses is recognized, there remains a paucity of research that disentangles these reciprocal associations at the between- and within-couple levels, particularly within non-Western populations. This study addresses these gaps by examining longitudinal dyadic interactions in cognitive functioning among middle-aged and older Chinese couples.

Five-wave data collected over a decade were derived from the China Health and Retirement Longitudinal Study (CHARLS), encompassing 6089 heterosexual couples. At baseline, the mean age was 54.99 years (SD = 9.51) for husbands and 52.83 years (SD = 9.13) for wives. Cross-Lagged Panel Model (CLPM) and Random Intercept (RI)-CLPM were utilized to distinguish between between-couple and within-couple mutual effects. Age and education level were investigated as potential moderators of these associations.

The between-couple findings revealed significant mutual effects among couples. Conversely, evidence for within-couple cognitive contagion was limited. Neither age nor education level moderated these reciprocal effects. Lower-educated wives tended to exhibit greater stability in cognitive functioning than their higher-educated counterparts.

The between-couple findings support the similarity-attraction theory and highlight gender-specific role transitions that influence cognitive aging, while the absence of within-couple cognitive concordance may be due to the length of assessment intervals or individual differences. These findings emphasize the need for future research with more frequent assessments and better control of trait-like characteristics to clarify these dynamics and support targeted cognitive health interventions for middle-aged and older couples.