Verified by 
It first happened on an airplane. Returning home from a long five days in Washington, DC, I allowed myself to stop working and watch the movie Million Dollar Baby. I hadn't seen it and wondered how a movie with such an awful title could have won the Best Picture Oscar. I had only the vaguest sense of what the movie was about.
Six years earlier and recently married, I had informed my wife that "chick flicks" were out. Take a girlfriend, I implored, not me. Unless something is blown up or Schwarzenegger, Stallone, or Eastwood was in the movie, I had screws to turn and holes to drill in my spare time. But Million Dollar Baby starred Eastwood, so it was in my wheelhouse. Since that time, I had had two daughters, so Disney supplies most of the movies I watch.
At the climax of Million Dollar Baby, the tear floodgates opened. And I mean opened wide. I was aware that all the snuffling and slurping was inappropriate, but I couldn't stop. I cried so much that I think the guy next to me thought I was having a breakdown (have you seen that movie!?)
So, why do we cry at movies? Cognitively, we know that the story we are watching is (usually) fictional and the actors are paid to play on our emotions. But still, we can't help it. I can understand crying when you see your child or spouse get a painful medical procedure, or even when you watch an injured person on the TV news, but at a movie?
In previous posts, I introduced the neuropeptide oxytocin as modulating empathy. Oxytocin engages brain circuits that make us care about others, even complete strangers. Perhaps surprisingly, oxytocin engages at the smallest suggestion that someone wants to connect to us. I've shown, for example, that a person's brain releases oxytocin when he or she is entrusted with money by a stranger. Could oxytocin make us cry in movies?
To see if movies cause our brains to release oxytocin, my graduate student Jorge Barraza designed an experiment where participants watched a video from St. Jude Children's Hospital in Memphis, Tennessee. One group saw a part in which a father discusses his 4-year-old son Ben's terminal brain cancer. The other half watched as Ben and his father spend a day at the zoo. You can see the video here.
Yes, it is really emotional. OK, take a short break to recover.
In research that will soon appear in the Annals of the New York Academy of Sciences, those who saw the highly emotional part of the video had a 47% increase in oxytocin as measured in blood. Controlling for distress (which was associated with elevated stress hormones), empathy was highly correlated with the spike in oxytocin. This is the first evidence for the speculation, often from my mouth, that oxytocin is a physiologic signature of empathy.
We also had subjects make decisions that involved money and other people to see if those who were empathically engaged are nicer. Participants were paid for agreeing to let us stick them with a needle (twice). When given a chance to share this money with someone else in the lab being similarly tortured, we found that empathy predicted generosity towards a stranger. Yes, these people were generous with their hard-earned blood money! And they couldn't even see the people to whom they were giving money, it was all done by a computer. Their generosity didn't even merit a thank you or a smile in return. Empathy made them generous anyway.
At the end of the experiment, we also asked if participants wanted to donate some of their money to the American Red Cross or St. Jude Hospital. Many of them did, even those who had already given money away to a stranger in the lab. We were surprised to discover that some people donated all of their remaining money to charity. Can you guess who responded the most to the emotional video? Yes, women released more oxytocin and were more empathic than men. They also gave twice as much to charity.
So, we may cry at movies because the oxytocin in the human brain is imperfectly tuned. It does not differentiate between actual human beings and flickering images of human beings. Either one is enough to kick oxytocin into high gear and impel our empathy. And it reveals why men like me avoid chick flicks—we don't want to be seen bawling when the guy finally gets the girl.
Well, if Clint Eastwood can cry in Million Dollar Baby, I guess I can shed a couple of tears, too.
