First read about this on Dustin Curtis’s blog, which describes an experiment where a mouse trained to find food at a rectangle will choose a more rectangular rectangle if the option presents itself.
Lesson: rather than look for specific patterns, animals identify a characteristic features and look for the “peak” instance.
Another example is V.S. Ramachandran’s Herring Gull Test, where he showed that gull chicks identify their mother’s beak via it’s red stripe. When he painted extra red stripes on a yellow stick, the chicks responded to the “beakier” version.
Here’s a fun essay on peak shift for aspiring artists, with this great closing statement:
In depictions of the human figure, Michelangelo’s over-the-top musculature, Renoir’s ample bottomization, and the distortions of El Greco, Giacometti and Modigliani give an idea of what’s to be had.
Much of this seems to come from the excellent BBC/PBS series How Art Made the World.
Surprisingly, there isn’t a page for this subject in wikipedia.