Happy couples take note. A new study suggests that divorce spreads through a social group like a virus, with the breakup of a friend's marriage vastly increasingly the possibility of one's own nuptials ending.

Researchers have dubbed the phenomenon "divorce clustering" and say a breakup between friends in your immediate social circle can increase your own chances of being divorced by 75 per cent.

Even a friend of a friend divorcing increases the likelihood of your own breakup by 33 per cent, the U.S. joint study by three academics from Brown University, Harvard University and the University of California says.

The researchers examined statistics taken from a group of individuals over a 32-year period.

The study also says it's not just friends that can affect your chances of divorce, siblings and co-workers can too.

Among the study's key findings

• Someone with a divorced sibling is 22 per cent more likely to get divorced
• Someone with a divorced coworker is 55 per cent more likely to get divorced than someone who works with all married coworkers
• Presence of children in marriage did not affect likelihood of divorce
• Divorcees lose up to 10 per cent of their friends
• Popular people are less likely to get divorced

The study, called "Breaking Up is Hard to Do, Unless Everyone Else is Doing it Too: Social Network Effects on Divorce in a Longitudinal Sample Followed for 32 Years," was done by political scientists Rose McDermott of Brown University and James H. Fowler of University of California, San Diego and sociologist Nicholas A. Christakis of Harvard University.

"Overall, the results suggest that attending to the health of one's friends' marriages serves to support and enhance the durability of one's own relationship, and that, from a policy perspective, divorce should be understood as a collective phenomenon that extends far beyond those directly affected," their report concludes.

According to Statistics Canada, about 38 per cent of Canadian marriages end by their 30th anniversary.

In the United States, about 44 per cent of marriages end with divorce.

In both the U.S. and Canada, divorce rates peaked in the 1980s and have fallen since.