It's an aching feeling of deep affection that many of us can barely control. When we see an adorable creature, we must fight an overwhelming urge to squeeze that cuteness with everything we've got. And pinch it, and cuddle it, and maybe even bite it.
This is a perfectly normal psychological tick - an oxymoron called "cute aggression" - and even though it sounds sadistic, it's not about causing harm at all. In fact, strangely enough, this compulsion may actually make us more caring.
The first study to look at cute aggression in the human brain has now revealed that this is a complex neurological response, involving several parts of the brain.
By triggering innate processes for caregiving, the authors of the study think that cute aggression stops us from getting emotionally overloaded by things that are super cute and may need looking after.
"Essentially, for people who tend to experience the feeling of 'not being able to take how cute something is,' cute aggression happens," explains lead author Katherine Stavropoulos, a researcher in cognitive science and neuropsychology at the University of California, Riverside.
"Our study seems to underscore the idea that cute aggression is the brain's way of 'bringing us back down' by mediating our feelings of being overwhelmed."
While cute aggression has been studied in the past, Stavropoulos' research is the very first to match this psychological phenomenon to actual patterns of brain activity.
For the first time, she and her team have directly shown that cute aggression is linked to activity in both the brain's reward system - responsible for feelings of "wanting" and pleasure - and the system that processes our emotions.
Using electrophysiology, the researchers mapped the brain activity of 54 participants between the ages of 18 and 40, each of whom were shown 128 photographs of cute human babies and cute animals.
The photographs featured a mix of baby animals, adult animals, normal human babies, and human babies that have been digitally "enhanced" to appear extra cute.
After each category of photographs was shown, participants were asked a series of questions about how overwhelmed they were by the images and whether they felt compelled to care for what they had just seen.
Similar to previous research from Yale, the findings reveal that cute aggression is not necessarily a universal phenomenon present in all humans.
Instead, it appears that some people are more susceptible to feelings of overwhelming cuteness, while others have never experienced these compulsions at all.
The study found, for instance, that about 64 percent of participants confessed to saying, "it's so cute I want to squeeze it" in the past, and about 74 percent admitted to actually acting on that impulse.
When it comes to cute baby animals, the participants were especially affected by cute aggression, reporting high levels of feeling overwhelmed, high levels of cute aggression, and high levels of care giving.
"There was an especially strong correlation between ratings of cute aggression experienced toward cute animals and the reward response in the brain toward cute animals," says Stavropoulos.
"This is an exciting finding, as it confirms our original hypothesis that the reward system is involved in people's experiences of cute aggression."
The authors of the paper propose that cute aggression is actually a 'regulating' response in the brain - an emotional shield that steps in to protect us when something is just too overwhelmingly cute and our reward system begins to spiral out of control.
"For example, if you find yourself incapacitated by how cute a baby is - so much so that you simply can't take care of it - that baby is going to starve," explains Stavropoulos.
"Cute aggression may serve as a tempering mechanism that allows us to function and actually take care of something we might first perceive as overwhelmingly cute."
So while cute babies and adorable animals may look completely helpless, their vulnerable appearance may actually help them survive.
Next, the researchers want to figure out what makes some people more likely to experience cute aggression than others.
"I think if you have a child and you're looking at pictures of cute babies, you might exhibit more cute aggression and stronger neural reactions," suggests Stavropoulos.
"The same could be true for people who have pets and are looking pictures of cute puppies or other small animals."
This study has been published in Frontiers in Behavioral Neuroscience.