A recent study offers the first systematic review of same-sex unions and divorce rates based on accurate national register data in Sweden from the 1990ís.
The study found that gay male couples were 1.5 times as likely (or 50 percent more likely) to divorce as married opposite-sex couples, while lesbian couples were 2.67 times as likely (167 percent more likely) to divorce as opposite-sex married couples over a similar period of time. Even after controlling for demographic characteristics associated with increased risk of divorce, male same-sex couples were 1.35 times as likely (35 percent more likely) to divorce, and lesbian couples were three times as likely (200 percent more likely) to divorce as opposite-sex married couples.
This is despite the fact that heterosexual and same sex couples generally face the same risks of divorce:
In general, characteristics associated with increased risk of divorce appear very similar for same-sex and opposite-sex partners: Younger couples, less educated couples, couples with greater age differences, couples where one partner was foreign-born, or where one or both partners had been previously married, were more likely to divorce. For example, Swedish partners with only a secondary education or less were more than twice as likely to separate as couples where both partners had a university degree.
Note even the presence or absence of children in the couple’s home family could explain the prevalence of divorce among same-sex couples.
The lower rates of children among same-sex couples did not explain this difference. Even among childless households, same-sex male partnerships experienced almost a 50 percent higher likelihood (1.49 times as likely) of divorce during the study period, while childless lesbian couples were three times as likely (200 percent higher likelihood) to break up as a married couple without children.
One reason children may not reduce the divorce risk on same-sex couples is that these children are less likely to be children of both partners and more often “stepchildren” for one partner. The authors speculate that there may be an indirect effect from the possibility of procreation in reducing divorce risk in opposite-sex marriages: “To some extent, the disruption risks of childless heterosexual spouses might be reduced in anticipation of childrearing, i.e., when spouses stay together in order to fulfill their plans of parenthood.”
See also these policy briefs from iMAPP.org on
sustained public resistance in the U.S. to same-sex marriage, and a decrease in support for SSM among college students