You may have heard of the neurotransmitter dopamine, which is strongly connected with desire and pleasure. Dopamine is a major part of the brain's reward system, so it is understandable to assume that it is the reward. It is popularly referred to as the pleasure chemical, after all. But this view is incorrect. Dopamine is the primary chemical behind desire and anticipation, but it isn't the pleasure chemical - it is better understood as the promise chemical.16
