Mark puts in long hours studying for hos psychology test he already has an a in the course but he really has the desire to

I believe the answer is: Intrinsic motivation

Intrinsic motivation refers to the type of motivation that driven by internal rewards. The things that included in intrinsic motivation could be things such as: you find the action somehow interesting, you get a certain amount of pleasure from the behavior, The behavior is necessary to fulfill your ambition, etc.