Abstract: A substantial increase in the availability of data on psychosocial traits in large representative longitudinal samples has opened up new areas of research for economists and new opportunities for collaborations with psychologists. As an example, I incorporate personality into alternative economic models of marriage, with individual traits associated with either productivity in home or market sectors, or preferences for household public goods. Empirically, personality traits have robust effects on individual propensities to marry and to divorce in a representative sample of the German population. Changes in these patterns across cohorts are consistent with a shift in the principal sources of marital surplus from production complementarities to consumption complementarities in the past few decades. Some personality traits related to divorce are also related to limited self-control in other domains, and suggest that departures from rational action should be considered in models of family behavior. In general, further analysis of the impact of personality and other psychological indicators on family relationships may improve our understanding of variation in partnership and parental decision-making, and of their responses to policy and to institutional environments.