• bisexual;
  • gay;
  • lesbian;
  • marriage;
  • social trends

The author used a new longitudinal data set, the How Couples Meet and Stay Together surveys (N = 3,009), to generate the first nationally representative comparison of same-sex couple stability and heterosexual couple stability in the United States. He measured the association between marriage (by several definitions of marriage) and couple longevity for same-sex couples in the United States. Reports of same-sex relationship instability in the past were due in part to the low rate of marriages among same-sex couples. After controlling for marriage and marriage-like commitments, the break-up rate for same-sex couples was comparable to (and not statistically distinguishable from) the break-up rate for heterosexual couples. The results revealed that same-sex couples who had a marriage-like commitment had stable unions regardless of government recognition. A variety of predictors of relationship dissolution for heterosexual and for same-sex couples are explored.