Why are babies and puppies considered universally cute?

Babies and puppies are considered cute because we are hardwired to respond positively to faces with big eyes but otherwise small features.

Women between the ages of 19 and 26 might be the group that responds most strongly to babies; if a young woman sees a baby, her pupils dilate, and it takes just a seventh of a second for the parts of her brain involved with the feelings you get when you see something you really like to light up.

All the same, almost everyone is a sucker for puppies, kittens, seal cubs, and other baby animals. Even tiny crocodiles or baby skunks seem cute. But what do we mean by cute, and why is it so appealing?

Cuteness is very strongly linked to neoteny, a biological term for when creatures keep features associated with very early stages of development. These features are strong signals that the creature in question is young and defenseless and needs looking after.

The most obvious neotenous features are those that are apparent in the face. Young creatures of most species tend to have disproportionately big heads compared to their bodies, and to have big eyes compared to their heads. In humans, babies have eyes that are almost adult sized, but their heads are smaller and their bodies relatively tiny. The eyes don’t grow much, but the rest of the body does, so by the time someone reaches adulthood, their eyes are proportionally much smaller.

The cut-off point for baby cuteness is around four and a half years old; children older than this are no longer seen as cute in the same way and do not trigger the same automatic responses from the adults looking at them. This age marks the point at which their features cease to appear neotenous.

For a lucky few, neoteny and its benefits extend into adulthood. Adults with features such as big eyes and small noses are generally viewed as more good looking, and men particularly find women with these features more attractive. The effects of neoteny can also cross species barriers so that humans respond to neoteny in other animals—hence, the perceived cuteness of puppies and kittens.

Why should we find cuteness so appealing and attractive? It seems to be hardwired into our brains as a means for making sure that we bond with and look after very young, helpless babies.

What does this have to do with men finding neotenous women sexy? Men probably evolved to be sexually drawn to those features that signal that a woman is young and fertile—and nothing signals youth like neoteny. Of course, neoteny signals too much youth and it doesn’t make evolutionary sense for men to find prepubescent girls attractive—but this may be an example of runaway sexual selection. This describes occurrences where one sex starts evolving certain features that indicate superior qualities, but once they get going, there is a sort of arms race that drives such features to exaggerated lengths. This is why, for instance, male moose have such huge antlers, and possibly why men have evolved such a hyperbolic desire for neotenous sexual features.

Disney babies

Other infantile features include button noses, small ears and chins, and rounded foreheads and faces. Most babies have these features, so we see them as being cute. This is why Barbie and Mickey Mouse both have enormous eyes. Such cuteness has real benefits. Cute babies get more attention and are more likely to be looked after. Babies with tiny eyes, flat foreheads, and square faces unfortunately tend to get less attention.