External motivation, such as rewards or punishments, can be effective in the short-term, but it can also lead to resistance and decreased motivation in the long-term. This is because external motivation is often seen as a form of control, and it can take away the sense of autonomy that is essential for intrinsic motivation.

Intrinsic motivation, on the other hand, comes from within. It is the desire to do something simply because we enjoy it or find it meaningful. Intrinsic motivation is more sustainable and leads to better performance in the long-term.