In one study, participants who worked alongside someone who rubbed her face or shook her foot were observed to produce the same behaviors. This mimicry illustrates:

the chameleon effect

Explanation:

The chameleon effect refers to nonconscious mimicry of the postures, mannerisms, facial expressions, and other behaviors of one's interaction partners, such that one's behavior passively and unintentionally changes to match that of others in one's current social environment.