The fact that friends influence their friends’ moods should be no surprise, but new research shows that friends-of-friends and friends-of-friends-of-friends—even those who’ve never met—have the power to influence each other’s moods, too.
The influence people hold over other people's moods wanes the further apart they are socially, according to the research reported in the New Scientist. A person is 15 percent more likely to be happy if a friend is happy, but it drops to ten percent for friends of friends, and six percent for friends three-degrees-removed. Six percent may sound like a small number, but a $5000 raise has been shown to bump contentment by just two percent.
The influence ends at three degrees of separation, according to the researchers. After that point, sway through social networks becomes insignificant. Interestingly, the study suggests that social influence doesn’t operate in a simple ripple effect—three is apparently the magic number. After three degrees of separation, “a kind of social dissonance saps the transmission of behavior, almost like a wave.”