Non-random mating and convergence over time for mental health, life satisfaction, and personality: the Nord-Trøndelag Health Study

Behav Genet. 2013 Mar;43(2):108-19. doi: 10.1007/s10519-012-9578-2. Epub 2012 Dec 22.


Earlier studies have shown evidence for various sources of observed spousal similarity regarding different traits and characteristics. We explored the relative contribution of non-random mating and convergence to spouse similarity with respect to global mental health, life satisfaction, optimism, and type A personality. We used population-based data collected for the Nord-Trøndelag Health Study (1984-1986) and prospective registry information about when and with whom people entered into marriage/cohabitation between 1970 and 2000 for 19,599 married/cohabitating couples and 1,551 future couples that entered into marriage/cohabitation during the 16 years after data collection. Couples were categorized by interval between data collection and entry into marriage/cohabitation. Age-adjusted polychoric correlations calculated for each group were used as the dependent variables in non-linear, segmented regression analysis, with time since or until marriage/cohabitation as the independent variable. Initial correlations between partners-to-be were low to moderate, typically around one-half of the values estimated in existing couples, indicating both non-random mating and early convergence. There appeared to be moderate divergence during the first 20 years of marriage/cohabitation and moderate convergence during the rest of life.

MeSH terms

  • Adult
  • Female
  • Humans
  • Male
  • Marriage / psychology*
  • Middle Aged
  • Norway
  • Personal Satisfaction*
  • Personality*
  • Spouses / psychology*