Do you know a smile when you see one?

Early European explorers in the Caribbean islands commented on the "abominable" and "frightening" figures in the locals' art, with their bared teeth and "burning" eyes. But a new analysis suggests that the artists may have intended these expressions as inviting smiles rather than demonic grimaces.

According to Dr. Bridget Waller, who co-published the research results in Current Anthropology, "Exposed and clenched teeth are not common features of aggression.... Regardless of the specific context, baring teeth is most probably about social bonding."