As this video shows, over the past 26 years, obesity in America has exploded. Much of that comes down to cultural changes, genes, new traditions, and a number of other things, but there’s another reason, too: obesity is contagious.
A few years ago, Nicholas Christakis and James Fowler analyzed data from the Framingham Heart Study to make this conclusion. As Wired’s Jonah Lehrer writes:
According to the data, if one person became obese, the likelihood that his friend would follow suit increased by 57 percent. (This means that the network is far more predictive of obesity than the presence of genes associated with the condition.) If a sibling became obese, the chance that another sibling would become obese increased by 40%, while an obese spouse increased the likelihood that the other spouse would become obese increased by 37%.
The researchers asked participants if, after seeing a picture of an obese friend, they would then accept a cookie if someone offered them one. Not surprisingly, most people said that seeing pictures of the obese friend would reduce their desire for a cookie. However, it turns out that, based on a number of similar situations, the opposite happens. Lehrer writes:
In one of their experiments, researchers asked random strangers walking through a lobby at the University if they would take a quick survey. The surveys had photos of an overweight person, a person of normal weight or a lamp. After completing the survey, the researchers asked the subjects to help themselves from a bowl of candy. Those who were exposed to the picture of the overweight individual took, on average, 3o percent more candies than those exposed to the control pictures.
It’s scary to think of obesity as some kind of bug, winding through whatever social network we’re a part of. But it’s also kind of amazing. This is what makes us human. We think and we do on our own, but we’re all inter-connected whether we realize it or not.
Now, get off your ass and try some of these.