Humans are not fooled by size illusions in attractiveness judgements.
Could signallers use size contrast illusions to dishonestly exaggerate their attractiveness to potential mates? Using composite photographs of women from three body mass index (BMI) categories designed to simulate small groups, we show that target women of medium size are judged as thinner when surrounded by larger women than when surrounded by thinner women. However, attractiveness judgements of the same target women were unaffected by this illusory change in BMI, despite small true differences in the BMIs of the target women themselves producing strong effects on attractiveness. Thus, in the context of mate choice decisions, the honesty of female body size as a signal of mate quality appears to have been maintained by the evolution of assessment strategies that are immune to size contrast illusions. Our results suggest that receiver psychology is more flexible than previously assumed, and that illusions are unlikely to drive the evolution of exploitative neighbour choice in human sexual displays.
Centre for Behaviour and Evolution and Institute of Neuroscience, Newcastle University, Henry Wellcome Building for Neuroecology, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
Melissa
M
Bateson
Centre for Behaviour and Evolution and Institute of Neuroscience, Newcastle University, Henry Wellcome Building for Neuroecology, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
Martin J
MJ
Tovée
Centre for Behaviour and Evolution and Institute of Neuroscience, Newcastle University, Henry Wellcome Building for Neuroecology, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
Hannah R
HR
George
York Neuroimaging Centre, University of York, York Science Park, York, YO10 5DG, UK.
Anton
A
Gouws
Department of Psychology, University of York, York, YO10 5 DD, UK.
Piers L
PL
Cornelissen
Body mass index; Ebbinghaus illusion; Mate choice; Physical attractiveness; Sexual selection; Size-contrast illusion