Michael D. Hill introduces RAMPS as a motivation model: Rhythm, Autonomy, Mastery, Purpose, Safety. Michael even goes deep on Mastery as Motivator: The M of RAMPS. Next, Ron Jeffries sings harmony. post 
Rhythm are periods of tension leading to periods of release. The coming and going of energy & intensity.
Autonomy is the sense of being able to control one’s own situation, a kind of freedom of action and responsibility within some broad boundaries.
Mastery is about development and growth—the idea that every person has in mind a better self they want to approach. Mastery is the sense of approach.
Purpose is the sense of belonging to a movement or activity that is more than just one person in the dark, it is the shared goal.
Safety is the belief that we are allowed to be different, even wrong, whether it be temporally local or temperamentally global.