We spend a lot of time talking about ourselves.

From Contagious: Why Things Catch On by Jonah Berger. Page 33.

Indeed, research finds that more than 40 percent of what people talk about is their personal experiences or personal relationships. Similarly, around half of tweets are "me" focused, covering what people are doing now or something that has happened to them. Why do people talk so much about their own attitudes and experiences?

It's more than just vanity; we're actually wired to find it pleasurable. Harvard neuroscientists Jason Mitchell and Diana Tamir found that disclosing information about the self is intrinsically rewarding. In one study, Mitchell and Tamir hooked subjects up to brain scanners and asked them to share either their own opinions ("I like snowboarding") or the opinions and attitudes of another person ("He likes puppies").

They found that sharing personal opinions activated the same brain circuits that respond to rewards like food and money. So talking about what you did this weekend might feel just as good as taking a delicious bite of double chocolate cake.

I am more interested in the facts than the possible psychological cause. 40-50% of what people communicate is centered on the self? Interesting and might be true, though I suspect that the standard deviation might be pretty high ranging from the tersely dour to the compulsive sharer.