Teeth may act as a form of human ornament display that signals mate quality to others, new research has suggested.

Published in the peer-reviewed open access journal PLOS One, the study – here – noted this part of the body may be similar to voice quality and waist to hip ratio in this regard.

Carried out by Colin Hendrie of the University of Leeds Institute of Psychological Sciences and Gayle Brewer from the School of Psychology at the University of Central Lancashire – who is also an Associate Fellow of the British Psychological Society – the investigation noted smiling plays an important role when it comes to physical attraction.

Above: Digital manipulations of tooth spacing and colour

The authors wrote: ‘Smiling is also one of the first indications of sexual interest in our species. Hence, one of the opening acts of any new sexual partnership is a mutual tooth display.’

In addition, it was shown that tooth colour and spacing can alter attractiveness levels, while people often react negatively when these measures deviate from usual levels.