You'd probably never describe a compliment as "orgasmic." But under the microscope, sincere flattery at least looks—if not feels—a little bit like foreplay.
When most people receive a compliment, it triggers the same reward centers in the brain—the ventral striatum and the ventral medial prefrontal cortex—that light up during sex, explains Christoph Korn, a postdoctoral fellow with the University of Zurich's Computational Emotion Neuroscience lab.
It's the former part of your brain that seems to be the most critical: In one study, when people received either praise or money while having their brains scanned by fMRI machines, the ventral striatum—which sits at the base of the forebrain—responded almost identically to both stimuli. (The ventral medial prefrontal cortex, meanwhile, largely seems to concern itself with decision-making as it relates to social situations, according to a 2014 analysis in Nature Reviews Neuroscience.)
The best praise, in turn, also seems to leave us wanting more of the resultant mini-high. "The better the compliment, the greater the activity of these regions," Korn says, noting that dopamine, a neurotransmitter which has been tightly linked with pleasure and addiction, is likely involved in the process. (Researchers, however, have yet to investigate this theory.)
"In a sense, a compliment could be regarded as a specific type of reward—basically, another person tells you, 'do that again,'" Korn explains. Compliments, however, do more than get us hooked on good or socially popular behavior. They might also help us learn, explains Sho Sugawawra, a researcher with the National Institute for Physiological Sciences in Japan.
Sugawawra's research suggests that after trying out a new skill—like cooking, running, or playing the guitar—receiving praise seems to improve the brain's ability to remember and repeat that skill. For the study, 48 adults were taught a finger-typing drill, striking a particular sequence of keys on a keyboard as fast as possible for 30 seconds. The next day, the participants who had been praised while learning the skill performed significantly better than everyone else.
Sugawawra and his colleagues believe that by increasing activity within the striatum, compliments improve learning that occurs while we sleep, which researchers call "skill consolidation." He notes that after 30 minutes of learning something new, your memory and performance actually start to decline, and they don't tend to peak again until you've slept.
Receiving praise could also make you more likely to push yourself toward situations in which you have to learn. Korn's findings demonstrate that when we receive feedback—good or bad—activity in areas of the cerebral cortex associated with evaluating and comparing ourselves to others increases. As a result of this process, called "mentalizing," the feedback informs how we feel about our abilities and our self-worth.
However, Korn notes that compliments influence our self-perceptions to a far greater extent than criticisms. Think of it this way: When you receive a positive performance review, you're more likely to take the credit. But when your boss chews you out, you're more likely to deflect the blame and write him or her off as an asshole.
That's called an "optimistic bias," and this tendency to absorb compliments and shrug off criticisms may have an evolutionary benefit. "Overestimating your abilities might prompt you to work harder, exercise harder, and approach new people and challenging situations," Korn says. "All of this may bear positive consequences that reinforce the initial optimism."
The result: You keep pushing yourself, and getting your fix.