Why We Melt at Puppy Pictures

Why We Melt at Puppy Pictures

Cute babies elicit caregiving behavior in humans—but why do we have the same response to the cute young of other species?

By Robert M. Sapolsky in the Wall Street Journal

Things were great at home. Everyone was getting enough sleep, cleaning all the laundry and dishes, and keeping up with homework. So it seemed like the obvious time to upend it all by getting a puppy.

Upend it the puppy did. At 2 a.m., with objects soiled or chewed up dotting the house, chaos reigned. 

I was about to lose it, and then the puppy did something unbearably cute. Misery evaporated, because the puppy was so adorable that I was going to eat him up, starting with his tiny wittle paws. This, of course, prompted the question: “Why is caregiving behavior being elicited from me by the infantile features of another species?”

Mammalian babies all look the same: short snouts, high foreheads, round faces, big eyes. And we love it. The more a particular baby’s features accentuate those traits, the cuter we rate the face. 

People, including children, prefer pictures of babies over those of adults, and they prefer cute babies over un-cute ones.

Brain-imaging studies show that looking at baby faces activates dopamine “reward” pathways in the brain: The cuter the baby, the higher the activation. (I’m full of empathy for the parents whose babies are used as examples of “not cute” in these studies.)

Baby features, it is thought, evolved to “release” caregiving behavior in adults—an adaptation that is no news to parents. Researchers have found that pictures of babies make their viewers more precise and careful in fine motor tasks, and make them pay more attention to small details. Poignantly, cuter babies elicit a deeper protective impulse: When subjects were shown pictures of babies and asked to rate their motivation to care for them, they were more inclined to attend to the beguiling beauties.

This helps to explain the evolution of baby cuteness and their parents’ responses. But why have this sort of response to the young of another species? It doesn’t help our evolutionary fitness to get all googly-eyed and have an urge to pay for piano lessons for a baby beluga.

It turns out that our brains aren’t great at differentiating between our own cute babies and those of animals. Stephen Hamann of Emory University has shown that viewing baby animals activates the same neural reward circuitry as looking at human babies.

Work by Jessika Golle and colleagues at the University of Bern in Switzerland shows this lack of differentiation more subtly. The research concerned “visual adaptation.” If you look at bright lights for a while, even normal lighting then seems dark. If you look at dim light, even normal lighting seems bright afterward. The authors showed that the same happens for cuteness.

Wallow in cute baby pictures, and afterward you will rate average-looking babies as uncute; look at lots of uncute babies and the opposite occurs. The same thing occurs when humans look at cute, average and un-cute puppies. After seeing lots of cute puppies, average-looking human babies look un-cute to us. Conversely, gazing at many uncute puppies makes us think that average human babies look cute.

In other words, the neural circuits that update what counts as cute do not pay attention to what species we are looking at: It’s not as if we’ve had to evolve distinctive safeguards against parenting the wrong species. The brain as a whole has no problem distinguishing human from nonhuman, cute or otherwise. Nevertheless, among humans, when it comes to adorableness, on a certain neurobiological level human baby = puppy = calf = fawn = piglet.

We sure are a unique species. Or are we? As shown by Anna Sato of Kyoto University in Japan and colleagues, Japanese macaque monkeys prefer to look at pictures of babies over adults of their species. The showstopper: When the macaques look at a species of monkey from another continent, they also prefer babies over adults.

What does this mean? That we are not alone: If they could just figure out how to do it, other primates would probably also waste hours each day looking at YouTube videos of adorable wittle puppies.