Marie climbed the stairs, each step seeming taller than the last, to her third-floor apartment. The door swung shut with a thud of finality into the silence of a midday apartment; her roommates were already gone. Kicking her shoes into a corner, she slouched into her bedroom, tossing off the apron and sitting slowly, her aching feet twinging as the weight was removed. With a wince, she leaned back and reached for her computer.

Sometimes, her job as a hostess set off her acute anxiety. The fact that her relationship was falling apart at home didn’t help either. The card for the therapist her mother recommended was still on the table, but she didn’t have health insurance through her employer, so that wasn’t an option on minimum wage. Instead, Marie turns to Reddit. Within a few minutes of scanning r/aww, the dozens of pictures of kittens, puppies and bunnies have calmed her down. She feels her muscles relaxing, and somehow, the stress of the day seems to drift away.

Marie uses cute pictures as self-medicated therapy. And for someone who has a minimal income and a high-stress environment, it’s a pretty brilliant improvised management tool.

Everyone reacts differently when they see something they think is cute, but nearly all reactions are somewhat physiological. A paper published in the PLOS One in 2012 entitled “The Power of Kawaii“—the Japanese word for cute—found that looking at photographs of animals and people perceived as cute improved attention span and focus. Therapy dogs have been introduced to college campuses during finals weeks as a way to reduce stress in many students. Personal anecdotes have told us that people feel more relaxed, less sick, more honest and more productive when there are cute things around them.

Then, of course, there are extremes. Not to pick on Japan, but that country does have a tendency to take cute a little too far. In the mid-1990s, a trend came out in Japanese fandom culture called “moe,” when individuals began to be obsessed with certain aspects of cute things. It bears dangerously close to fetishization of particular aspects of women particularly and has been somewhat controversial in anime culture. However, there is a trope of people passing out or getting nosebleeds from something being too cute.

But this is off-point. Why do we find things cute in the first place? This is a subject of some debate.

Some researchers believe that we find rounder heads, smaller faces with larger eyes and small bodies cute because they are infantile, and evolutionarily, we have an advantage if we find our infants cute. (i.e., they survive infancy.) This idea was put forward by Konrad Lorenz, a prominent ethologist who also happened to be a member of the Nazi Party in the1930s before rejecting their ideology when he saw the horrors of the concentration camps.

However, another school of thought says that hormones are secreted when we see something we are attached to, forming a positive response. A 2006 study found that there is a gender difference, with women noticing smaller differences in cuteness than men. But in both schools of thought, the perception of cuteness is thought to contribute to our bonding with the young.

Baby animals, particularly baby mammals, share many characteristics with baby humans: Round heads, big eyes, smaller body parts that look like miniatures of the larger. We find them cute because of the characteristics they share with humans, probably. The feelings they evoke in us are likely side effects of bonding, hormone secretion and brain waves telling us that these things need to be protected.

What is most interesting is the differences in culture. Cuteness to us can be perceived as creepiness in another culture. As the word widens thanks to the Internet and mass communication, it can show us more about our development and the diversity among humans and other forms of life from its first moments.