Mimicking the behavior of the people you are talking to makes you appear friendlier to those people.

If you’ve ever had the “annoying childhood friend” who just copies everything you say when he/she begins to lose the argument, then you probably don’t believe this. However, according to the Chartrand and Bargh experiment; subtly mimicking another’s body language, speech inflection, and facial expressions can increase your likeability. 

This is known appropriately as the Chameleon Effect. It occurs perhaps because conversations feel smoother when each person can understand and relate to the way the other communicates and acts. The experiment was divided into 3 parts and asked 78 individuals to engage in various exchanges with one experimenter. 

It was discovered that individuals whose moves had been imitated had rated their experimenters as more likeable, and that when confronted with an experimenter who was different from themselves, individuals actually mimicked the experimenter’s actions. People who were more open to other people’s ideas mimicked more than those who weren’t. 

The results of this experiment seem to indicate that in an average social setting, it’s not just the effect of the mimicry, but also the mimicry itself, that occurs unconsciously. According to Chartrand; “Those who pay more attention mimic more,” and end up making a good reputation for themselves. So perhaps the “annoying childhood friend” was on the right track. 

(Source)