Why do small rewards make us want to repeat an action?

The brain's reward system, including areas such as the ventral striatum, helps learn which actions lead to beneficial outcomes. Dopamine is not simply a pleasure chemical; it is crucial for signaling reward prediction and motivating future behavior. When a reward is unexpected or variable, the response can be especially strong, which helps explain why habits can form around games, notifications, and other intermittent rewards. This principle is central to much of modern behavioral psychology and neuroscience.