This study examines gender and marital status differences in psycholog
ical well-being across an extensive array of measures using data from
a sample of non-Hispanic, White, midlife adult participants in the Wis
consin Longitudinal Study, 1992-1993 (N = 6,876). Evidence for how sel
ection and social causation might account for differences also is eval
uated. Multivariate analyses reveal several gender interactions, usual
ly indicating a greater disadvantage for unmarried men than for unmarr
ied women. Separate analyses by gender show a complex picture of both
positive and negative effects of being single. Contrary to what the se
lection argument hypothesizes, single women have higher scores on rela
tively enduring personality characteristics associated with better psy
chological well-being than married women. Single men do not compare so
favorably with married men. Overall, selection does not account for m
arital status differences in well-being. Household income and having a
kin confidant mediate some of the remaining effects.