When you've acted in an uncooperative or untrustworthy way, the way you smile could either help heal or hinder social relationships. Those whose smiles reflected reward, or a signal that they were happy, or a smile of dominance, which reflects a feeling of superiority, appeared to be untrustworthy and unlikely to change their deceptive nature. However, a smile of affiliation was perceived as an attempt to make amends, restoring levels of trust.
