Science Reveals Why We Brag So Much

By Robert Lee Hotz, WSJ 
Talking about ourselves—whether in a personal conversation or through social media sites like Facebook and Twitter—triggers the same sensation of pleasure in the brain as food or money, researchers reported Monday.
About 40% of everyday speech is devoted to telling others about what we feel or think. Now, through five brain imaging and behavioral experiments, Harvard University neuroscientists have uncovered the reason: It feels so rewarding, at the level of brain cells and synapses, that we can’t help sharing our thoughts.
“Self-disclosure is extra rewarding,” said Harvard neuroscientist Diana Tamir, who conducted the experiments with Harvard colleague Jason Mitchell. Their findings were published in the Proceedings of the National Academy of Sciences. “People were even willing to forgo money in order to talk about themselves,” Ms. Tamir said.
“It rings true to me,” said psychologist James Pennebaker at the University of Texas at Austin who studies how people handle secrets and self-disclosure, but was not involved in the project. “We love it if other people listen to us. Why else would you tweet?”