From shelter dogs to stickleback fish, the forces that shape animal personality are surprisingly familiar.

We tend to think of wild animals as being spared from the messy business of personality: the family dramas, the psychological wounds, the baffling quirks that keep resurfacing like whack-a-moles.

Turns out, nobody gets out of that. Animals have personalities, too, and many of the same complex forces that shape our personalities shape theirs.

“They’re not spared,” says Dr. Alison M. Bell, a behavioral ecologist at the University of Illinois Urbana, tells Popular Science. “Life is hard for them, too.”

But life is also “rich,” says Bell, full of ups and downs, wounds and triumphs, just like human lives.

It’s one of those truths that is both surprising and incredibly obvious, especially for those of us with pets. And yet the study of animals’ personalities has faced resistance—in part because accepting it means accepting that animals are far more like us than some are willing to admit.

Personality and social psychologist Dr. Sam Gosling noticed a telling pattern among his colleagues in animal research: On coffee breaks, they’d talk freely and enthusiastically about the personalities of the animals they studied, even their pets at home. Then the break would end.

“They’d finish their tea breaks, put on their scientist white coats, and stop any kind of talk about that,” he says.

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