As it turns out, there may be a biological answer.
What babies and pizza have in common
Biological anthropologist Gwen Dewar has researched this phenomenon and come up with some incredible results. She talks about an experiment in which 30 women were exposed to either the smell of newborn infants or just plain ole' air.
Some fancy-pantsy brain scans revealed that the reward center of the brain lit up when the women smelled that special newborn smell. Coincidentally it's the same area of the brain that lights up when we eat our favorite foods ... or consume mind-altering drugs.
Therefore, one explanation (or contributing explanation) could be that we bite cute things because our brains associate them with delicious food. Weird, right?
Why you get the urge to bite
Another possible explanation comes right from the animal kingdom. Many animals (like puppies) playfully nip at other animals in a teasing manner, but it could be more than just a playtime activity.
Researchers from the anthropology department at the University of California observed capuchin monkeys carefully bite each other firmly but not hard enough to cause pain. They suggest it may be how these monkeys form bonds of trust and alliance with each other.
Like our mammal friends, biting could be a way we test and foster strength in a relationship with someone we love.
Why you get the urge to squeeze
In addition to biting, sometimes seeing something adorable really brings out some aggression. You know what I'm talking about. "It's so cute I just want to squeeze it to death," or "It's so fluffy I'm gonna die!"
A couple of Yale graduate students wanted to figure out why, so they ran a few experiments. In one experiment they showed 90 participants a bunch of different images of animals. Some were funny, some were neutral and some were cute. Oh, and they gave their participants bubble wrap.
They found a strong link between viewing cuteness and aggression. Participants who viewed cute animal pictures popped an average of 50 more bubbles than those who viewed funny pictures.
Researchers are calling it cute aggression. That urge you get to hug that cute little kitten as tightly as you can is totally normal.
Check out this awesome video for more details about cute aggression and to see the bubble wrap experiment successfully replicated:
And there you have it. The next time you want to chomp on some chubby baby or want to snuggle it until the end of time, you know a little more about why.