For years, I’ve had the following on my website:

I believe that relationships are the most important part of our lives. I believe in a concept called the law of associations, which says that you tend to become the average of the five people you spend the most time with, in every way: health, habits, outlook, income, creativity, exercise, ambition, etc….

It turns out that I should have added obesity to that list. That’s the latest in the New England Journal of Medicine.

I was turned onto this idea by Jim Rohn’s work, several years back when I was rabidly devouring personal development books, audio & video. A friend and colleague from those days, John Mann, writes the following in his blog entry The Company You Keep:

Experience bears this out—but I’d never seen any actual scientific proof that this was so. At least, until this morning: the Law of Association now has an interesting tidbit of confirmation—from the New England Journal of Medicine, no less. As reported in The New York Times, a retrospective analysis of data from the famous 32-year Framingham Heart Study found that when “Obesity can spread from person to person, much like a virus.” When a subject’s friend became obese, even if living at a distance of hundreds of miles, the subject had a 57 percent greater chance of becoming obese him- or herself. And between “close mutual friends” the odds of the influence increased to 171 percent.

It is uniquely satisfying to get scientific backup for a belief you held without real proof.