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We love talking about ourselves, we really do — that’s what a group of Harvard neuroscientists found while testing the theory that we’re big on self-disclosure, anyway. In fact, say the scientists, we love self-disclosure so much because it tickles our core value centers in much the same way as “primary rewards” like food and sex.

Citing studies of human conversation, Harvard researchers Diana Tamir and Jason Mitchell note that we devote 30% to 40% of what we say in life to telling others about our own experiences. Surprising? Not so much? After all, it goes in hand-in-glove with longstanding beliefs about our proclivity to spin narratives, i.e. we’re born storytellers, it’s just that a third or more of those stories involve us.

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What’s more, say the researchers, Internet surveys indicate that over 80% of social media posts to sites like Facebook, Twitter and others amount to “announcements about one’s own immediate experiences.” That certainly jibes with my experience, reading this morning about one person’s sinus problems, another’s uninspiring breakfast and a third’s toilet relocation problems (whether we enjoy reading about other people’s experiences is, of course, another matter).

Tamir and Mitchell wanted to know why, specifically, we’re so jazzed about self-disclosure, so they decided to test recent theories that people talk about themselves because it triggers brain mechanics associated with rewards. Using both neuroimaging and “cognitive methods,” they scanned the brains of individuals who alternately talked about their own beliefs and opinions or speculated about the beliefs and opinions of others. The researchers also threw money into the mix as a fixed reward to test participants’ willingness to forego cash in order to talk about themselves.

No surprise, they found that self-disclosure activates parts of the brain that form the mesolimbic dopamine system — widely associated with our so-called “desire” and “reward” mechanisms. They independently charted the “reward” regions by first testing with “some money” vs. “no money” and mapping brain activity, then testing the same regions for activity during self-disclosure. As expected, the regions lit up much more frequently when individuals talked about their own beliefs and opinions than when assessing those of others. But since these regions have also been shown to react to non-rewards, the researchers performed a second study involving a fixed reward (money) to mitigate ambiguity about their results.

In the second study, the researchers asked participants to answer questions like “How much do you enjoy winter sports such as skiing?” (self-disclosure) and “How much does Barack Obama enjoy winter sports such as skiing?” (judgment of another’s opinion), then associated small cash amounts with each question (paid to individuals at the experiment’s close).

The result: Participants once more chose self-disclosure more frequently. When the payoff amounts were equal, for instance, they chose to answer self-disclosure questions nearly three-quarters of the time. The researchers’ conclusion: “Just as monkeys are willing to forgo juice rewards to view dominant groupmates and college students are willing to give up money to view attractive members of the opposite sex [a reference to prior studies], our participants were willing to forego money to think and talk about themselves.”

Intriguingly, the researchers noted a distinction between types of self-disclosure: introspection, or privately thinking about oneself, compared with having the opportunity to share those thoughts with another human being. Again, as expected, while introspection was itself sufficient to light up brain regions associated with reward, the effects were “magnified” when participants believed their thoughts would be communicated to someone else.

Though the research establishes an empirical basis for talking about what actually happens when we self-disclose and how it relates to regions of the brain associated with rewards, there’s still the evolutionary question: Assuming this research holds up, why did we evolve this way? According to Tamir and Mitchell:

In an ultimate sense, the tendency to broadcast one’s thoughts and beliefs may confer an adaptive advantage in individuals in a number of ways: by engendering social bonds and social alliances between people; by eliciting feedback from others to attain self- knowledge; by taking advantage of performance advantages that result from sharing one’s sensory experience; or by obviating [removing] the need to discover firsthand what others already know, thus expanding the amount of know-how any single person can acquire in a lifetime. As such, the proximate motivation to disclose our internal thoughts and knowledge to others around us may serve to sustain the behaviors that underlie the extreme sociality of our species.

This last part reminds me of something literary theorist Kenneth Burke once expressed, when he wrote that language is “a symbolic means of inducing cooperation in beings that by nature respond to symbols.” Paired with the Harvard study, it suggests we like to talk about ourselves — now more than ever through social media channels — in part because, even in our most innocuous-seeming missives, we’re attempting to bring others around to our way of thinking about reality.

Tamir and Mitchell’s study was recently published in PNAS, a publication of the National Academy of Sciences. You can view a copy of it here.

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