Having siblings may reduce risk of divorce

Growing up with siblings may reduce a person's risk of divorce, and the more siblings the better, according to new research presented at this year's Annual Meeting of the American Sociological Association.

The practical difference in divorce risk between having no siblings and having one or two isn't that much, said Doug Downey, co-author of the study and a professor of sociology at The Ohio State University.

"But when you compare children from large families to those with only one child, there is a meaningful gap in the probability of divorce," he said.

That gap is about t percent per sibling, up to about seven siblings, which means the difference between an only child and a person with one sibling was surprisingly negligible.

"We expected that if you had any siblings at all, that would give you the experience with personal relationships that would help you in marriage," said Donna Bobbitt-Zeher, co-author of the study and an assistant professor of sociology at Ohio State.

"But we found that the real story appears to be how family dynamics change incrementally with the addition of each sibling," Bobbitt-Zeher said. "Having more siblings means more experience dealing with others, and that seems to provide additional help in dealing with a marriage relationship as an adult."

The study used data from the General Social Survey, which involved interviews with about 57,000 adults from across the United States at 28 points between 1972 and 2012, and the good effects of multiple siblings was seen across all generations studied.

Even after controlling for variables including education, socioeconomic status, family structure, race, age at marriage, whether the respondents had children, gender role attitudes, and religious affiliation, the sibling effect remained.

The study itself does not explain the protective effect of having siblings, but researchers say the implication may simply be that practice makes perfect.

"Growing up in a family with siblings, you develop a set of skills for negotiating both negative and positive interactions," Downey said. "You have to consider other people’s points of view, learn how to talk through problems. The more siblings you have, the more opportunities you have to practice those skills."

Even so, there are many other factors that contribute to divorce, whether one has siblings or not.

"There is a relationship between the number of siblings and divorce, but it is not something that is going to doom your marriage if you don’t have a brother or sister," Bobbitt-Zeher said.