This weekend my youngest daughter and I went to see the new movie Coco. The movie is a multi-layered parable about how family connections transcend time.

The penultimate scene shows a boy singing a lullaby to his great-grandmother who suffers from dementia. The song, Remember Me, was written by her father and they would sing it together each time he said goodbye to her when she was a little girl.

I won’t spoil the significance of this song but as a father of three little girls, what happened next brought a few tears of joy trickling down my cheek.

After the movie, my daughter asked me, “They were happy tears, right daddy.” After confirming, she said as a matter of fact, “Kids don’t cry happy tears.”

Which got me wondering. Do they? And what exactly are happy tears?

To begin, crying itself is part of an emotional regulatory process with a very real health benefit.

Our emotional tears contain stress hormones and the act of crying produces endorphins (a natural pain killing chemical). So for many reasons, crying makes us feel better.

Why we cry happy tears is more of a mystery. Some hypothesize that in instances where we have “come a long way” to achieve a goal – whether graduating college or winning a championship, our pained tears have been bottled up or suppressed and we are now overwhelmed to the point of expressing them at a time of joy.

Another theory is that when we are overwhelmed by a positive emotion, say the birth of a child or our wedding day, we cry to help us recover and get back to a state of emotional equilibrium. In other words we cue a negative response (crying) to help us cope with being overwhelmed by a positive one (joy).

Which brings us back to the question posed by my daughter. Do children cry happy tears?

In one scenario, it would mean that our children have experienced significant early life struggles to trigger happy tears when they achieve their goals.

In the other, it suggests that they connect deeply to their emotions and have figured out a healthy way to respond to them.

In either case, happy tears are heavy ones. We want our children to feel deeply but not too deeply and not too early.

The fact that my six year old doesn’t think kids cry happy tears is probably a good thing and so I hope is the fact that her father cries them all the time.