“Supernormal stimuli” redirects here. For the book by Deirdre Barrett, see Supernormal Stimuli.

Venus of Willendorf, figurine exaggerating body and breast stimuli.
A supernormal stimulus or superstimulus is an exaggerated version of a stimulus to which there is an existing response tendency, or any stimulus that elicits a response more strongly than the stimulus for which it evolved.

For example, it is possible to create artificial bird eggs which certain birds will prefer over their own eggs, particularly evident in brood parasitism. Some speculate humans can be similarly exploited by junk food. Organisms tend to show a preference for the stimulus properties (e.g. size, colour, etc.) that have evolved in nature, but when offered an artificial exaggerated stimulus, animals will show behaviour in favour of the artificial stimulus over the naturally occurring stimulus. A variety of organisms display or are susceptible to supernormal stimuli, including insects, birds, and humans.

Supernormal stimuli are present in areas of biology and psychology, but are also studied within other fields like sociology and art.

British academic Nigel Spivey demonstrates the effect in the first episode of the 2005 BBC documentary series How Art Made the World to illustrate neuroscientist Vilayanur S. Ramachandran’s speculation that this might be the reason for the exaggerated body image demonstrated in works of art from the Venus of Willendorf right up to the present day.