THE BLOG

The Seven-Year Expiration Date on Friendships

06/28/2009 05:12 am ET | Updated Nov 17, 2011

It's always exhilarating to make a close friend -- a soul mate -- someone you understand and who makes you feel understood. When this happens, it feels like the bond will last a lifetime. Yet most friendships, even the best of them, don't last forever.

Recent research by Dutch sociologist Gerald Mollenhorst at Utrecht University confirms that the large majority of friendships tend to be fleeting. He found that both the friends we make and the ones we keep are more likely to be determined by opportunity rather than personal preferences. Many relationships fall apart because people no longer have the opportunity to be together in the same context, e.g. a school, an office or a neighborhood.

The sociologist surveyed 1007 men and women between the ages of 18 and 65 years and was able to re-interview 604 of them seven years later. Over that time, the size of an individual's social network remained strikingly stable (in terms of numbers) but there was a lot of turnover: New friends replaced old ones and only thirty percent of the original friendships remained. The influence of social context (where they met) on longevity was remarkably similar for friends and acquaintances -- irrespective of the closeness of the relationship.

One implication: If a friendship is meaningful, it needs to be nurtured.

Do most of your relationships have a shelf life?

Source: Press Release, Netherlands Organization for Scientific Research, May 27, 2009

Irene S. Levine, PhD is a freelance journalist and author. She holds an appointment as a professor of psychiatry at the New York University School of Medicine and is working on a book about female friendships, Best Friends Forever: Surviving A Break-up With Your Best Friend, that will be published by Overlook Press in September, 2009. She recently co-authored Schizophrenia for Dummies (Wiley, 2008). She also blogs about female friendships at The Friendship Blog.