Why your number of romantic partners mirrors your mother

Results suggest that mothers may pass on personality traits and relationship skills that make their children more or less likely to form stable relationships.

"Our results suggest that mothers may have certain characteristics that make them more or less desirable on the marriage market and better or worse at relationships," said Claire Kamp Dush, lead author of the study and associate professor of human sciences at The Ohio State University.

"Children inherit and learn those skills and behaviors and may take them into their own relationships."

The study was published today (11-13-18) in PLOS ONE.

While a lot of research has found that children of divorce are also more likely to divorce, this new study broadens the picture, Kamp Dush said.

"It's not just divorce now. Many children are seeing their parents divorce, start new cohabiting relationships, and having those end as well," she said.

"All of these relationships can influence children's outcomes, as we see in this study."

Data came from the National Longitudinal Survey of Youth 1979 (NLSY79) and the National Longitudinal Survey of Youth Child and Young Adult (NLSY79 CYA). Both surveys have followed the same participants for at least 24 years.

All the people in the NSL79 CYA survey were the biological children of women in the NLSY79, so the researchers could get a long-term look at the number of partners for people in both generations. The surveys included information on not just marriage and divorce, but also cohabiting relationships and dissolutions.

The surveys are run by Ohio State's Center for Human Resource Research.

This study included 7,152 people in the NLSY79 CYA survey.

Both the number of marriages and the number of cohabiting partners by mothers had similar effects on how many partners their children had, the study found.

However, results showed that siblings exposed to their mothers' cohabitation for longer periods had more partners than their siblings exposed to less cohabitation.

"You may see cohabitation as an attractive, lower-commitment type of relationship if you've seen your mother in such a relationship for a longer time," Kamp Dush said.

"That may lead to more partners since cohabitating relationships are more likely to break-up."

The study discussed three theories about why children tend to follow their mothers in terms of the number of relationships.

One theory has been that many people dissolve relationships because of the economic instability associated with divorce and cohabitation dissolution; one partner's income is usually lost. Economic hardship can lead to poorer child outcomes and a more difficult transition to adulthood, leading to more unstable partnerships in adulthood, the theory says.

While economic instability was indeed related to the number of partners a person had, controlling for economic factors in the study did not significantly reduce the mother-child link in the number of partners. This means money problems were likely not the main reason behind why many people follow the path of their mothers when it comes to relationships.

A second theory suggests that the actual experience of observing your mother going through a divorce or breaking up a cohabitation -- or multiple breakups -- leads children to have more partners themselves. According to this theory, an older half-sibling who saw his or her mother go through multiple partners should be more at risk than a younger half-sibling who wasn't exposed to as many partners.

But this wasn't the case, Kamp Dush said. A sibling who experienced his or her mother moving from relationship to relationship did not have a statistically greater number of partners compared to a sibling who did not experience instability.

So what does explain why mothers and their children share partnering trends?

"What our results suggest is that mothers may pass on their marriageable characteristics and relationship skills to their children -- for better or worse," Kamp Dush said.

"It could be that mothers who have more partners don't have great relationship skills, or don't deal with conflict well, or have mental health problems, each of which can undermine relationships and lead to instability. Whatever the exact mechanisms, they may pass these characteristics on to their children, making their children's relationships less stable."