Laughter is Contagious
The discovery of mirror neurons—what causes you to smile when someone smiles at you—gives credence to the belief that laughter is contagious.
When you’re feeling down finding friends to laugh with can help your brain trigger its own laughter response and foster closeness, both of which contribute to your sense of well-being. Why do you think that sense of humor is such an important trait when looking for a partner? We like the feeling of shared laughter and our body wants as much of this feeling as possible.