Hey, did we tell you how we know why people brag? Y'know because we're pretty smart and all, and we read the Wall Street Journal, like all smart people do.
Anyhoo. Here's why:
People brag for all sorts of reasons, she says: to appear worthy of attention or love or to try and cover up our deepest insecurities. To prove to ourselves that we're OK, that people from our past who said we wouldn't measure up were wrong. Or simply because we're excited when good things happen to us.
And talking about ourselves feels good. According to the results of a series of experiments conducted by Harvard University neuroscientists and published in May in the Proceedings of the National Academy of Sciences, the reward areas of our brain—the same areas that respond to "primary rewards" such as food and sex—are activated when we talk about ourselves. We devote between 30% and 40% of our conversation time to doing just that, according to the study, which didn't focus on boasting specifically, but on self-disclosure.
In one experiment, the researchers offered people small amounts of money to answer questions about themselves or others. They generally were willing to forgo earnings in order to talk about themselves.
Elizabeth Bernstein explains further why bragging is getting worse now that people have Facebook: Link