Monkeys Fall Into ‘Uncanny Valley,’ Just Like Humans

Monkeys are freaked out by almost-but-not-quite-real depictions of themselves. That tendency is well documented in humans, but has never before been seen in another species.

To test their preference, researchers showed macaque monkeys real pictures, digital caricatures and realistic reconstructions of other monkey faces. To the latter, the macaques repeatedly averted their eyes.

“The visual behavior of the monkeys falls into the uncanny valley just the same as human visual behavior,” wrote Princeton University evolutionary biologists Shawn Steckinfinger and Asif Ghazanfar in a paper published Monday in the Proceedings of the National Academy of Sciences.

The “uncanny valley” was identified in 1970 by Japanese roboticist Masahito Mori, who noticed that people presented with likenesses of increasing realism respond with increasing empathy, right up to the point where the likenesses are almost real. At that point, people are repulsed. The sudden dip in graphs describing their response gave the phenomenon its name.

Wired.com