Not only do we unconsciously copy the mannerisms of others, but we like and have smoother interactions with strangers if the stranger copies our mannerisms. Unconsciously, a connection is formed, and you “like” people who are similar to you. If we have been mimicked, we are also more helpful toward other people who are present than are nonmimicked individuals. We also tend to agree with others we like.
Gazzaniga, Michael S. Who’s in Charge?: Free Will and the Science of the Brain. New York: Ecco, 2011