Finding people you want to spend time with can be a challenge when life gets in the way. Rebecca G. Adams, a professor of sociology and gerontology at the University of North Carolina at Greensboro, explains the phenomenon like this: As external conditions change (people coupling off, having kids, changing jobs, etc.), it simply becomes tougher to meet the three conditions that are considered crucial to making close friends: proximity; repeated, unplanned interactions; and a setting that encourages people to let their guard down and confide in each other. Laura L. Carstensen, a psychology professor who is the director of the Stanford Center on Longevity in California, points out: although people tend to interact with fewer people as they move toward midlife, they do grow closer to the friends they already have. For those who do want to find new friends, Dave Cervini, a radio station executive who moved to New York in his 30s only to find himself extremely lonely, created the New York Social Network, an activities group for people to find friends by spending time together at Yankees games or wine-tasting mixers. The group now boasts 2,000 members, most in their 30s.

The New York Times, 7/15/2012