(Drawing courtesy of Neitram) Humans feel a surge of affection for animal babies like their own, with large eyes, bulging craniums and retreating chins.
Why Baby Animals are "Cute"
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MAY 06, 2009
April Holladay, HappyNews Columnist

What is the thing that makes all young animals look cute to us humans? And do they generally look less cute when they mature? Joe, Singapore
Baby animals (and some adults) look cute because they resemble baby humans.
The 1973 Nobel Prize winner zoologist Konrad Lorenz lists babyhood features that few can resist: "A relatively large head, predominance of the brain capsule, large and low-lying eyes, bulging cheek region, short and thick extremities, a springy elastic consistency and clumsy movements." Also, playfulness. What human can watch tiger cubs wrestle or pounce on one another without a smile?
These characteristics distinguish our young from adults, and trigger an affectionate, nurturing response, Lorenz theorized. It's basic; we must help our young survive, when they are least able to help themselves, or our species would die.
Babies did not, however, evolve to look or act cute. Our species changed to recognize our young's special features — not the other way around.
Moreover, this ability to recognize immature members is general among primates and all mammals, emails biologist Michael C. LaBarbera of the University of Chicago. Our species inherited its ability to recognize our young's special features. Furthermore, at least some species (including humans) seem to generalize this recognition. For instance, "Koko the gorilla adopted a kitten and, just a few years ago, a female gorilla at Chicago's Brookfield Zoo protected a child that had fallen into the gorilla exhibit."
Primate bodies (and all mammalian bodies) develop in much the same fashion dictated by survival needs — not a cuteness requirement.
A disproportionately large head houses a large brain. A newborn macaque monkey's head is more than three times heavier than an adult's, relative to their body weights, writes anthropologist Adrienne Zihlman of the University of California at Santa Cruz. Even at birth, a primate's brain contains the development a baby needs to survive. He can see, hear, feel, smell and cling. For the development he lacks — primarily muscles (for locomotion, finding food and protection) — he relies on his mother.
In fact, all baby mammals have large heads, says LaBarbara, primarily because their bodies produce most brain nervous tissue while in utero. Baby mammals have short snouts relative to cranium size; their snouts elongate as the animal approaches weaning. Probably this is why squirrels seem cute. Even as adults, they tend to have short snouts.
But the baby must change. "All mammals go through a regular series of shape changes as they grow and mature," says LaBarbera.
A newborn's body has almost equal amounts of skin, bone and muscle. As he matures, the amount of skin and bone in his body shrinks relative to his entire body mass while his muscle-mass almost doubles (changing from 25 to 42% of total body mass), says Zihlman. Now, an adult, he can handle life; he needs no triggered kindness. And, in general, he doesn't look cute anymore.
Further Reading:
D.R. Bolter and A.L. Zihlman. "Primate growth and development. A functional and evolutionary approach." Invited paper for Primates in Perspective, S. Bearder, C. Campbell, A. Fuentes, K. McKinnon, editors. Oxford University Press. 2006.
The biology of B_movie monsters by Michael C. LaBarbera, University of Chicago, Organismal Biology & Anatomy, Geophysical Sciences, the Committee on Evolutionary Biology
Konrad Lorenz. Part and Parcel in Animal and Human Societies, in Studies in animal and human behavior, vol. 2. pp. 115-195. Cambridge, Mass.: Harvard UP, 1971 (originally pub. 1950).
Readers contributed answers to this question. The next question is: Can an average person develop the skill to reliably detect liars? Click here to give April your answer. Deadline: June 29. We will publish the best answers on July 13.
Readers' Answers to the current question:
The perception that immature animals are "cute" is a mechanism to curb our natural hunting instincts and allow our prey to mature to an age of procreation before we start hunting them for food.
Humans are arguably the most successful and prolific predators in the history of planet Earth, no other species has been able to cause the types of mass extinctions that I have witnessed in my short lifetime, and immature animals are the easiest of prey. If something didn't stop us from eating animals before they're old enough to procreate we would quickly exhaust our supply of animal protein, a ready source for high-quality proteins, which our metabolisms require to survive.
If you believe in creation, it's easy to understand this as part of God's plan. If you believe in evolution, it's easy to see a group of humanoids without the "cute filter" would target immature animals for food, quickly wiping out species by species in their region until finally no animals would be left. The lack of a high-protein food source would lead to a type of malnutrition known as Kwashiorkor, leading to a decline and eventual disappearance of the group and removing that group from the gene pool. Only the groups with the "cute filter" would survive and grow to contribute to our modern population.
Rob Donelson, Texas, USA
All young animals look cute to humans because youth represents the potential of life, and it is human nature to be attracted to the potential of life. All of the potentials of evolution lie within the brand new life form.
Jaycee, Fayetteville, North Carolina, USA
Because they might look cute to most mammals and the reason for that might be that evolution provided us (and other mammals) with this feeling of them being cute so we (and other mammals) don't harm them or even help them when we see them in trouble. This might be the way the evolution tried to prevent the extinction of those species that need protection when they are young. When they are grownups, other rules of relation between species apply, so they don't need to look cute any more. Although some still do.
Jim Jast, Wayland, Massachusetts, USA
Pre adolescent animals, due to the fatty tissues stored in their bodies during their mother's pregnancy, cause animals and even children to appear more "cuddly". The difference in their appearance vs. an older animal encourages the nurturing instincts in mother animals. By the time these fatty tissues are completely exhausted and hormonal changes take place at puberty, they have lost the cute image and generally go to a long lanky look while their muscles grow. At maturity, the muscles have caught up and the lanky look goes away. This explains why parents lose their desire to be parents when their offspring become teenagers.
Frank, Atlanta, Georgia, USA
I believe the reason humans tend to think "baby" animals are cute is because they can be controlled, or at least we think we can. A small lion cub or bear cub might be fun to play with on your lap...but you probably wouldn't think so when they get six months to a year old.
Barry, Shelbiana, Kentucky, USA
In fact, every young thing looks more beautiful. Take humans, for example, a child looks more beautiful. But to ME a mature animal is also beautiful. A dog, even if its a fully grown one, will look equally innocent.
Lahore, Punjab, Pakistan
(Answered May 11, 2009)