Michael Shermer,

“Of all the chemical transmitter substances sloshing around in your brain, it appears that dopamine may be the most directly related to the neural correlates of belief. Dopamine, in fact, is critical in association learning and the reward system of the brain that Skinner discovered through his process of operant conditioning, whereby any behavior that is reinforced tends to be repeated. A reinforcement is, by definition, something that is rewarding to the organism; that is to say, it makes the brain direct the body to repeat the behavior in order to get another positive reward.”