Similarities in cognitive abilities in older couples: a study of mutual influences

Objective: Similarities between spouses in cognitive functions have been mainly explained by the assortative mating phenomenon and the convergence for age and education. The mutual influence between spouses is another explanation particularly relevant in the elderly population. Today, it remains difficult to determine whether cognitive similarities exclusively result from the convergence effect or from the mutual influence. Using a novel methodology, the present study aimed to assess the impact of the marital relationship on cognitive similarities among elderly couples.Methods: 1723 couples from the Three-City Cohort Study were classified in two groups of couples with homogeneous and heterogeneous age and education. We also constituted two groups of pseudo-couples by a random association of individuals, with homogeneous and heterogeneous age and education. Dyadic analyses were conducted in the four groups, regarding the similarities in lexicosemantic abilities, executive functions, memory and global cognitive functioning.Results: Similarities were found on lexicosemantic abilities both in mate-assorted couples and in couples heterogeneous in age and education but no similarity was found in pseudo-couples.Discussion: Beyond the convergence effect, the fact that the spouses co-construct their lifestyles may contribute to cognitive similarities in the lexicosemantic domain.