Babies. Adorable, chunky babies. Rolls and rolls, folding over and under one another. Drinking in all that delicious newness just makes us want to hold them and take care of them at this little stage of life, forever.

Rest assured, mama, your urge to devour your baby is backed by evolution, biology and plenty of research. Not only is it normal, it’s healthy.

Babies are designed to help people to fall in love with them. Ginormous eyes and bitty noses above rosebud lips, chubby necks, squishy arms and legs, all add up to pure sweetness—making us want to take care of them and yes, even eat them, too.

These compulsions are part of an evolutionary bonding mechanism and signify positive emotions and healthy attachment, in addition to helping us decrease our stress levels by releasing pent-up energy and emotional overload. Several studies have provided insight into the biological foundations of human caregiving and a neurobiological explanation for why we feel these urges.

In short, we are hardwired to be drawn to, care for and “want to eat” anything that looks like a baby.

Evolution and science conspire to make us nibble

Ethology is the study of human behavior and social organization from a biological perspective. It’s also the field of science in which it is proven that babies are cute for a reason—to attract us and make us want to care for them.

Cute physical characteristics are defined by ethologist Konrad Lorenz as “baby schema.” Over the eons we have come to subconsciously associate round faces, large eyes, big foreheads and small chins as cute or “baby.” Just look at dolls, cartoon characters, advertising and even car designs—hello, Volkswagen Bug—to see Lorenz’s theory IRL.

In a submission to the journal of Proceedings of the National Academy of Science (PNAS), a team of researchers tested the impact of baby schema on the perception of cuteness and the motivation for caretaking in 122 undergraduate students. Using morphing techniques, they manipulated photographs of 17 infant faces to produce images of high baby schema, or “cute” (round face, high forehead, big eyes, small nose and mouth), and low baby schema, or “not cute” (narrow face, low forehead, small eyes, big nose and mouth).

The students viewed both categories, along with the original portraits of each infant, then rated the infants’ cuteness and how much they were motivated to take care of them. Portraits with the most baby schema (babies rated “cutest”) correlated with the strongest impulse to cuddle and provide protection and care to the infants.

Interestingly, other studies have indicated that women tend to be more interested in infants and caretaking activities than men. Based on this, the scientists further hypothesized that women would have a higher response to baby schema than men. So in their next study, the researchers set out to determine the neural basis of this altruistic maternal instinct.

Related: To the mama questioning herself—your instincts are right on, according to science

In this second study, 16 women who had never given birth were chosen to view a random sequence of the same set of infant faces from the first study while their brain activity was measured. During the session, the women rated the pictures for cuteness.

Using functional magnetic resonance imaging (fMRI) to map their brain activity, researchers were able to see that regardless of whether the women were the babies’ mothers, higher baby schema activated the mesocorticolimbic system, which is the neural network affiliated with reward. The release of dopamine—the feel good hormone—from the mesolimbic pathway into the nucleus accumbens regulates motivation and desire and facilitates reward-related motor function learning.

The scientists surmised that perceiving high baby schema infants as “cute” presents a positive incentive, via the surge in dopamine, that provides the motivational drive for caretaking behavior. This engagement of the mesocorticolimbic system proves a biological foundation for human caregiving by providing a neurobiological explanation as to why we feel the urge to care for anything that resembles a baby.

Related: It’s science: A major factor in child development? The mother’s mindset.

From an evolutionary standpoint, being hard-wired to respond to baby schema in babies other than our own is adaptive, “as human ancestors likely evolved as cooperative breeders with a social system characterized by the spread of the caretaker role to group members other than the mother.”

Like modern-day alloparenting, the additional bonding to and protection by people other than kin that baby schema elicits in humans is integral in the promotion of the species. Simply put, it really does take a village.

Though cuteness can motivate us to care for anything that looks like a baby, it can also overstimulate us, throwing our brain into overload—and we. want. to. bite.

But how does all of this explain why we want to eat babies?

In 2015, two studies were conducted by graduate psychology students at the Clark Relationship Lab at Yale University. Researchers Oriana Aragon and Rebecca Dyer determined that too much cute stimuli (in this case, baby schema) triggers an aggressive reaction—or opposite expression.

Cute aggression, or “dimorphous expression,” is when an abundance of positive emotions elicits expressions normally associated with negative emotions.

In their first study, participants were shown pictures of babies that were so cute they overwhelmed them with positive feelings and caused them to reveal expressions of high aggression, saying they wanted to pinch the babies’ cheeks and “eat them up.” As expected, participants had more positive feelings when viewing photographs of cuter babies than when viewing photographs of the less-cute babies.

“When you see something that’s unbearably cute, you have this high positive reaction,” said lead researcher, Oriana Aragon. “These feelings get overwhelming, and for some reason (with) cuteness, the ‘dimorphous expression’ happens to be the gritting of teeth, clenching of fists and (the stating of) aggressive statements like ‘I wanna eat you.'” Basically, when we feel happiness that is so intense, it manifests as a violent impulse.

So why do we do this?

It’s a means of releasing stress.

Too many positive emotions can be as stressful and overwhelming as too many negative emotions—and it is just as bad for our bodies. “Being very high or really low still releases stress hormones, and it’ll still be hard on the body,” explains Aragon. “To regulate those emotions and regain balance and emotional equilibrium, we need to release stress in an opposite way, ie. aggressively.”

Aragon explains, “We regulate emotions in a lot of different ways. Sometimes we try to rethink the situation. Sometimes we try to push our emotions down with sheer will. Sometimes we remove ourselves from the situation that is causing the emotions. And with this new discovery, we are figuring out that sometimes we respond with the opposite expression from what we feel, and that seems to help to balance us back out too.”

So in a second study, Aragon and Dyer set out to determine if cute aggression in reactions to infantile stimuli indeed functioned to regulate emotion, and in the process, decrease stress levels.

In this second study, those who had the highest “aggressive” responses to the photos, ie. the most overstimulation, also tended to have a lower level of positive emotion five minutes after viewing the images, leading the researchers to believe that “cute aggression” was helping them regulate and balance out their overall emotions. “(P)eople who (express aggression) seem to recover better from those strong emotions,” explained Aragon.

This is a good thing: It is the brain’s way of bringing us back into a normal, more manageable range of emotions. Because, if we are out of control, we cannot care for our baby. In terms of evolution, a stressed mama, whether she is upset or overjoyed, might not be the most attentive mama, so nature has built in a way to even the keel and keep us alert, stable and able to act.

The researchers’ work is reinforced by other studies that have also concluded that by balancing one emotion with the expression of another, the expression of that emotion functions to regulate the other emotion.

Nature’s way of balancing emotions has wide reaching benefits

What scientists are learning from this phenomenon is being explored as a means for possibly alleviating mental illness. “You see (bipolar) people go manic for days—they’re really high, they’re really up. That has deleterious effects on the body. Potentially, this (research) could lead to better therapies… for people who are having a difficult time managing their emotions,” says Aragon.

Recognizing the benefits of the emotional release and balance gained from this phenomenon, Aragon and Dyer believe further studies can help people understand relationships and emotional states better.

So, mama, it is perfectly normal and healthy to want to eat your babies.

Cuteness motivates us to want to care for babies, but we can be overwhelmed by it, making us want to eat them. That aggressive response reduces the stress we get from all that incapacitating joy, and it all works together to balance out our overwhelming emotions so that we can continue to care for them and keep them safe.

And as far as your friends wanting to eat your baby, primatologist Susan Perry at the University of California, Los Angeles, and her colleagues say that harmless “social biting” may also be part of our evolutionary heritage as a way of testing our social bonds and displaying signs of our good intentions.

So go ahead and nibble on those cheeks—it’s making you a more emotionally balanced person, which makes you an even better parent.

This post was originally published May 07, 2018. It has been updated.