Understanding Intrinsic Motivation in Behavior

According to motivational theories, different factors can influence an individual's behavior. One important concept is intrinsic motivation, which refers to engaging in a behavior because it is personally rewarding. This contrasts with extrinsic motivation, where a person performs a behavior to receive external rewards. Consider the following scenario: Alex decides to take up painting classes. He reports feeling fulfilled and happy while painting, regardless of whether he sells his artwork or receives any accolades. In the context of motivational concepts, what best explains Alex's behavior?