Growing up with more siblings may reduce divorce risk, says study

People with three or more siblings are less likely to divorce later in life than people with one or two, suggests a new study presented Tuesday at the American Sociological Association in New York City.

Researchers from Ohio State University analyzed data from 57,061 American adults in the General Social Survey. The survey was based on phone interviews with different groups of 1,500 people polled every year or two between 1972 and 2012. About 80 per cent of people had gotten married, and of those, 36 per cent had since been divorced.

They found that for each additional sibling (up to about seven) a person's risk of divorce was reduced by 2 per cent.

"One of the ideas ... is the possibility that growing up with siblings and having lots of sibling interaction develops the kind of social skills that are potentially useful for maintaining a stable marriage later on in adulthood," study co-author Doug Downey tells CBS.

He says that having no siblings or just one or two doesn't make much of a practical difference.

Also see: Sibling rivalry is harmless? Not so fast

"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 tells Agence France Press.

The researchers controlled for factors like education, socioeconomic status, race, age at marriage, as well as religious affiliation. They suggest that none of these elements had any bearing on the connection between siblings and likelihood of divorce.

"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," says Donna Bobbitt-Zeher, a co-author of the study.

However, the idea that people with siblings are more socially well-adjusted has been questioned by previous research from 2011. The researchers of that study say that the differences in adult sociability among only children are insignificant.

"We're not in the 1950s, where mom might stay home and [an only child] would interact all day with an adult. No kids do that anymore," sociologist S. Philip Morgan at the University of North Carolina-Chapel Hill tells USA Today. "There are lots of opportunities to gain interpersonal skills."

Also see: Is divorce really the answer?

Morgan is referring to the idea that kids gain interpersonal and negotiating skills at school, an idea espoused by Lauren Sandler, author of One and Only, a book about only children.

Furthermore, demographer Paul Amato from Pennsylvania State University warns that social science studies are hard to interpret accurately.

"It would have to be replicated multiple times before you can have too much faith in it," he says.

It's worth noting that the authors of the most recent Ohio State University study have conducted prior research on only children, and conclude that "the previously observed social skills deficit among only children in kindergarten appears to be overcome by adolescence."