Social Selection and Social Causation in Marriage and Health: Longitudinal Evidence of Body Weight Change

Social selection proposes that health influences marriage, whereas social causation proposes that marriage influences health. We used biennial 1979 National Longitudinal Survey of Youth data to examine body weight 6 years before and 6 years after entering and exiting first marriages. For marital entry, social selection occurred as lighter women entered marriage. Social causation was not observed because all marital entry groups gained weight at comparable rates. Cohabitation was not associated with weight change after marital entry. For marital exit, short-term social causation occurred as men and women lost weight after marital exit and then regained equivalent weight. Overall, body weight change sometimes followed transitions into and out of marriage, but the associations were few in number, short-lived, and had no long-term impact on body weight.