It happens at the end of every rom-com: the good-looking guy gets the good-looking girl and they live happily ever after. Or do they?

A recent study suggests that in reality attractive people are more likely to have shorter relationships and experience divorce.

Christine Ma-Kellams, a social psychologist, led a team of Harvard researchers to investigate the impact of looks on relationship stability and to see if beautiful people had beautiful relationships. They did not.

She found that while, for instance, Brad Pitt may regularly top the polls as the world’s most desirable man, women should be careful what they wish for. As both Jennifer Aniston and Angelina Jolie have found out, he is not the finest marriage material. Neither, though, is Scarlett Johansson, who filed for divorce from her second husband this month and has confessed that monogamy was not for her.

The researchers began their study by asking two women to judge the attractiveness of 238 men in high school yearbook pictures. They then accessed ancestry.com to uncover the men’s marriage and divorce data in the 30 years since they left school. The men who were rated as more facially attractive were also more likely to have had shorter marriages.

Next the participants were asked to rate the attractiveness of 130 celebrities, using actors and actresses from the Internet Movie Database website and Forbes’s list of the most powerful celebrities. The findings revealed a similar pattern, with the better-looking celebrities more likely to have suffered marital problems.

To explore why this might be, Professor Ma-Kellams and her team focused on the theory that attractive people are more inclined to cheat.

While most of us begin to see others as less attractive once in a committed relationship, attractive people may lack such a protective bias. This was demonstrated in two more studies, in which attractive participants with exclusive partners were still shown to find others more attractive, an effect accentuated if they were dissatisfied with their relationship. This was not the case for those participants considered unattractive.

Previous research has suggested another reason that attractive men in particular are likely to stray more: they have the means and opportunity. If it is purely sex they are after, however, they might be out of luck. Attractive women have been found to care less for casual sex because they are in a better position to get what they want: a committed, long-term relationship.

This divide between how the sexes use their attractiveness in relation to mates is, in part, probably because social constructs reward men for having multiple sexual partners but criticise women. The findings of Professor Ma-Kellams’s team, published in the journal Personal Relationships, should console those who have been cut adrift by a dreamboat, but they also add to evidence that looks are not everything. A previous study revealed that having an attractive partner meant others would treat you with less compassion.

“We should be more mindful of the limitations of our own valuation of physical attractiveness. Everyone wants it, but depending on your relationship goals it may not be the best predictor of long-lasting relationships,” Professor Ma-Kellams said.