Married couples are less likely than other couples to fight about jealousy - but when they do, it's much more damaging, researchers at the University of British Columbia and the University of Iowa have found.

Their study showed that without jealous conflict, three-fourths of the married individuals surveyed were extremely satisfied with the emotional aspects of their marriage.

However, the chances of having that same level of satisfaction dropped to less than half if jealousy entered the equation.

For unmarried cohabiting couples, the probability of being highly emotionally satisfied only fell about eight points with jealousy. A similar contrast was observed for physical satisfaction.

"We associate certain rewards with marriage, but there are risks to it as well," said Anthony Paik, assistant professor of sociology in the UI College of Liberal Arts and Sciences.

"The advantages to marriage include deep commitment and trust. But when jealousy occurs in a marriage, that tension can have devastating effects on emotional and physical satisfaction. It's not a straightforward story that marriage produces happier relationships," he added.

Paik along with Mariana Gatzeva of the Department of Human Kinetics at the University of British Columbia analyzed a survey of 681 heterosexual men and women in marriages, cohabitant or non-cohabitant relationships from the Chicago area.

Participants answered questions about whether they had experienced sexual jealousy and their level of physical and emotional satisfaction with their relationship.