Why Your Brain Keeps Finding Faces in Things That Do Not Have Faces

A power socket looks surprised. The front of a car looks angry. A cloud has developed eyebrows. A slice of toast appears to contain a disappointed old man.

This phenomenon is called face pareidolia.

We see a face where no actual face exists.

That sounds like a simple mistake. It is actually evidence of how aggressively the human visual system searches for socially important information.

Faces matter enormously to us. They tell us where another person is looking, what they may be feeling, whether we know them and whether the thing approaching us is potentially interested in cooperation, conversation or murder.

Missing a face could historically be expensive. Mistaking a rock for one costs very little.

So our face-detection system appears to favour sensitivity. Give it something vaguely face-shaped and it may begin processing before the rest of the brain has established that this is, in fact, a kettle.

Brain-imaging research supports this. Illusory faces briefly recruit parts of the visual system involved in real face perception. The effect happens rapidly. For a short moment, your brain processes the pattern as face-like before object recognition catches up and reminds everyone that you are staring at a washing machine.

It gets stranger.

People do not merely see faces in objects. They assign those faces expressions.

One building looks cheerful. Another looks furious. A handbag looks concerned.

Experiments have found surprising agreement between people about the emotions supposedly displayed by these entirely nonexistent faces. Other research found that people are much more likely to perceive ambiguous object-faces as male than female. Apparently even household appliances have acquired demographic bias.

Pareidolia is not evidence that your imagination is unusually active. It is normal perception operating under uncertainty.

Your brain would rather report a possible face and correct itself afterward than require a passport photograph before acknowledging one.

Which explains why the Moon has a face. Cars have faces. Houses have faces.

And somewhere in your kitchen, the toaster is judging you.