People may be hardwired to prefer cute and ugly animals over other humans, a new study suggests.

A team of researchers from UCLA and the California Institute of Technology (Caltech) says that neurons in the amygdala, which is an area of the brain that processes emotional reactions, responded preferentially to images of animals.

Researchers studied 41 epilepsy patients at the Ronald Reagan UCLA Medical Center.

They used electrodes that were already in place to record single-neuron responses in the amygdala while the patients looked at images of animals, landmarks, objects or people.

Our study shows that neurons in the human amygdala respond preferentially to pictures of animals, meaning that we saw the most amount of activity in cells when the patients looked at cats or snakes versus buildings or people, lead author Florian Mormann and former Caltech postdoctoral scholar said in a Caltech statement.

And the level of animal cuteness is irrelevant, according to researchers.

This preference extends to cute as well as ugly or dangerous animals and appears to be independent of the emotional contents of the pictures, Mormann said.

Researchers were surprised by the results of the study.

Nobody would have guessed that cells in the amygdala respond more to animals than they do to human faces, and in particular that they respond to all kinds of animals, not just dangerous ones, coauthor and Caltech professor Ralph Adolphs said. I think this will stimulate more research and has the potential to help us better understand phobias of animals.

The research results were published online in the journal Nature Neuroscience.