White explorers couldn't recognise a smile on native symbols
But an analysis of human and primate behaviour indicates that the motifs were more likely symbols of non-aggression and good will, similar to a smile.
Dr Bridget Waller, co-author of the report, said the misunderstanding of the motif by Europeans could have affected the way they treated the indigenous people on the islands.
When first encountered by European explorers, the bared teeth motif was characterised variously as a death mask, an image of a skull, and as the face of a shaman in trance.
Fernández de Oviedo y Valdez, who travelled to the Caribbean in the early sixteenth century, wrote that the grinning idols represented an "abominable figure...deformed and frightening with ferocious fangs and teeth and disproportionate ears and burning eyes of a dragon."
Modern scholars have previously agreed with the original interpretation that the figures represented a ferocious devil image or shamanistic trance, but the new study is the first to consider the image as a positive symbol.