Intrinsic and Extrinsic Motivation

Intrinsic motivation comes from inside the activity itself: you read because the story pulls you in, you play guitar because it feels good to play. Extrinsic motivation comes from something outside the activity: a grade, a paycheck, a gold star. Both can get the same behavior started, but they run on different fuel. The overjustification effect happens when you take an activity someone already does for intrinsic reasons and bolt an extrinsic reward onto it. The mind only needs one good explanation for why it's doing something, and an obvious, concrete reward is an easier explanation to grab onto than a vague inner feeling of enjoyment. So the person reattributes their own behavior: 'I read because I get paid,' not 'I read because I love it.'

The classic pattern has three stages. Before: a child reads for fun, no reward involved, intrinsic motivation is intact and measurable by how much they read with nobody watching. During: cash is offered per book, and reading often goes up, since now two motives are pushing the behavior. After: the reward program ends, and reading drops below the original baseline. The external reward didn't just fail to add motivation permanently, it corroded the intrinsic motivation that was already there, because the activity's meaning quietly shifted from 'thing I love' to 'thing I get paid for.'

Timing changes everything. A reward that is promised in advance sets up an explicit if-then deal in the person's mind, which is exactly what gets internalized as the 'real' reason for acting. A reward that shows up as a total surprise afterward can't have been the motive, since the person had no way to expect it, so it does far less damage to intrinsic motivation. This connects to attribution concepts elsewhere in the unit: people build explanations for behavior, their own included, and whichever cause is most salient tends to win.