Obesity is contagious

Fumento explains:

The basic premise of obesity as contagion is simple: The more something becomes prevalent, the more it becomes acceptable and the more of it you get. In a vicious cycle, more divorces begat more divorces, more unwed pregnancies begat more unwed pregnancies, more tattoos and piercings begat more self-mutilation (er, "body art") and so on. Obesity isn't just a physiological problem of too many calories in and too few out; it's a long-term social problem.

I am wondering if stupidity is contagious.