Nancy decided to take introductory psychology because she has always been interested in human behavior. Jack enrolled in the same course because he thought it would be easy. Nancy's behavior was motivated by , while Jack's was motivated by .

Intrinsic motivation; extrinsic motivation

Explanation:

Nancy decided to take introductory psychology because she has always been interested in human behavior. Jack enrolled in the same course because he thought it would be easy. Nancy's behavior was motivated by intrinsic motivation, while Jack's was motivated by extrinsic motivation.

Intrinsic motivation is a type of behavior or motivation that is driven by internal rewards such as the satisfaction of fulfilling a purpose/living for a purpose or self satisfying desires, while extrinsic behavior is a behavior motivated by external rewards such as promotion at work, good grades as in the case of Jack.