What's in a "like"? Well, a good deal of influence over how other people will perceive something, the New York Times reports. A study that manipulated positive and negative reactions to website comments found that one "like" prompted people to follow suit, while negative votes had no effect. In fact, readers of a comment with one fake "like" were 32% more likely to like it, and those comments scored 25% higher than others overall.
"That is a significant change," says MIT professor Sinal Aral, one of the researchers. "We saw how these very small signals of social influence snowballed into behaviors like herding." The study calls into question the value of ratings on websites like Amazon and Yelp, the Times notes, and could help marketers make their products more popular. "Hype can work," says Aral, "and feed on itself as well."