An interesting study demonstrates that we are able to make fairly accurate assessments about the internal states of others, based on their physical appearance alone.

Observers were able to accurately judge some aspects of a strangers personality from looking at photographs, according to a study in the current issue of Personality and Social Psychology Bulletin PSBP, the official monthly journal of the Society for Personality and Social Psychology. Self-esteem, ratings of extraversion and religiosity were correctly judged from physical appearance.

via Personalities accurately judged by physical appearance alone.