People around you control your mind: The latest evidence

in the Washington Post: “…That’s the power of peer pressure.In a recent working paper, Pedro Gardete looked at 65,525 transactions across 1,966 flights and more than 257,000 passengers. He parsed the data into thousands of mini-experiments such as this:

If someone beside you ordered a snack or a film, Gardete was able to see whether later you did, too. In this natural experiment, the person sitting directly in front of you was the control subject. Purchases were made on a touchscreen; that person wouldn’t have been able to see anything. If you bought something, and the person in front of you didn’t, peer pressure may have been the reason.
Because he had reservation data, Gardete could exclude people flying together, and he controlled for all kinds of other factors such as seat choice. This is purely the effect of a stranger’s choice — not just that, but a stranger whom you might be resenting because he is sitting next to you, and this is a plane.
By adding up thousands of these little experiments, Gardete, an assistant professor of marketing at Stanford, came up with an estimate. On average, people bought stuff 15 to 16 percent of the time. But if you saw someone next to you order something, your chances of buying something, too, jumped by 30 percent, or about four percentage points…
The beauty of this paper is that it looks at social influences in a controlled situation. (What’s more of a trap than an airplane seat?) These natural experiments are hard to come by.
Economists and social scientists have long wondered about the power of peer pressure, but it’s one of the trickiest research problems….(More)”.