New research from Dr. Robin Dunbar, an evolutionary psychologist at Oxford, claims that the physical act of laughing can trigger the release of endorphins in the brain. These brain chemicals, known for their feel-good effect, play an important role in our health. For instance, endorphin levels are connected to pain resistance; the higher your endorphins the less likely you are to suffer from crippling pain.
To test the relationship of laughter of this sort to pain resistance, Dr. Dunbar did a series of six experiments. In five scenarios, participants watched excerpts of comedy videos, neutral videos or videos meant to promote good feeling but not laughter. In the lab experiments, the participants were tested before and after seeing different combinations of videos. Wearing an ice cold sleeve, participants were asked to say when the pain reached a point they could not stand.
The results showed that laughing increased pain resistance, whereas simple good feeling in a group setting did not.
These findings support growing theories that laughter contributes to group bonding and may have been important in the evolution of highly social humans. By laughing together, humans came together to form groups.