This spring, a couple of neuroscience researchers at Harvard published a study that finally explained why we like to talk about ourselves so much: sharing our thoughts, it turns out, activates the brain’s reward system. As if to demonstrate the thesis, journalists and bloggers promptly seized the occasion to share their own thoughts about the study, often at a considerable cost to accuracy. “Oversharing on Facebook as Satisfying as Sex?” the Web site for the Today show asked.
Well, not really. The study, which combined a series of behavioral experiments and brain scans, didn’t suggest that anyone, in the lab or elsewhere, had found sharing on Facebook to be an orgasmic experience. What it did suggest was that humans may get a neurochemical reward from sharing information, and a significantly bigger reward from disclosing their own thoughts and feelings than from reporting someone else’s.
The Harvard researchers—Diana Tamir, a grad student in psychology, and Jason Mitchell, her adviser—performed functional MRI scans on 212 subjects while asking them about their own opinions and personality traits, and about other people’s. Neuroimaging of this sort can reveal which parts of the brain are being activated; in this case, the researchers found that the mesolimbic dopamine system—the seat of the brain’s reward mechanism—was more engaged by questions about the test subject’s own opinions and attitudes than by questions about the opinions and attitudes of other people. The system has long been known to respond to both primary rewards (food and sex) and secondary rewards (money), but this was the first time it’s been shown to light up in response to, as the researchers put it, “self-disclosure.”