By Emma Young

Why do we sometimes stay friends with ex-partners? There may be many reasons, but according to a new paper in Personality and Individual Differences they fall into seven main categories – and men and women don’t quite see eye-to-eye on them. The research also found that certain personality traits were related to motivations for staying friends after a break-up.

Justin Mogilski and Lisa Welling at Oakland University, US, asked a group of 348 volunteers to think of as many reasons as possible for why two former partners might want to remain friends. This resulted in a 153-item list.

A second group of hundreds more people – all of whom who had gone through at least one break-up (and were overwhelmingly exclusively heterosexual) – rated the importance of each item on a scale of 1 – 5. Then they completed personality questionnaires, including one tapping features of pathological personality, such as the tendency to experience negative emotions, antagonism (aggression and grandiosity), and sensation-seeking.

From the ratings, Mogilski and Welling identified seven main categories of reason for wanting to stay friends with an ex:

Reliability/sentimentality (e.g. “They made me a better person.”)

Pragmatism (e.g. “They had a lot of money.”)

Continued romantic attraction (e.g. “I still had feelings for them.”)

Children and shared resources (e.g. “Me or my ex was pregnant.”)

Diminished romantic attraction – which could cause a friendly relationship to lose its sexual aspect (e.g. “I lost sexual interest.”)

Social relationship maintenance (e.g. “To prevent awkwardness in our friend group.”)

Sexual access (e.g. “To keep having sex with them.”)

Overall, participants rated the reliability/sentimentality reasons as most important and practical reasons as least important.

There were some gender differences: men gave higher scores to practical and sexual access reasons than women did. Still, when certain aspects of personality (extraversion, honesty/humility and antagonism) were controlled for, the gender difference was only slight – in other words, men and women with similar personalities tended to give similar reasons. In particular, participants of both sexes who scored more highly on the trait of antagonism and/or on extraversion, gave higher ratings to practical reasons for maintaining a friendship. Extraversion in men and women was also associated with being motivated to maintain a friendship to continue sexual encounters.

Another link with personality was that people who experienced more negative emotions put a higher importance on reliability/sentimentality reasons, and continued romantic attraction. This could be because they suffer greater psychological distress during a break-up, and staying friends with an ex who can offer continued support and romantic interest may mitigate this, the researchers suggested.

Other work has found that friendships with former partners are common, and about half of divorced people report continued contact two and ten years after separating.

The new findings suggest that friendships after break-ups may provide an opportunity for ex-partners to continue to exchange desirable resources – such as love, status, information and money, Mogilski and Welling write in their paper.

There are a few limitations with the study, however. The mean age of the participants was 21.4 years in the first group and 21 in the second. Arguably, university students have only limited experience on which to base many of their judgements, and relatively few will have personal experience of reasons relating to pregnancy and children. Rather than seeking participants’ general attitudes to this issue, future work could also benefit from asking people about the motives behind specific post-relationship friendships they’ve experienced.

—Staying friends with an ex: Sex and dark personality traits predict motivations for post-relationship friendship

Image: Gwyneth Paltrow and Chris Martin attend the 3rd annual Sean Penn & Friends HELP HAITI HOME Gala on January 11, 2014 in Beverly Hills, California. (Photo by Kevin Mazur/Getty Images for J/P Haitian Relief Organization).

Emma Young (@EmmaELYoung) is Staff Writer at BPS Research Digest