There are perhaps three paradigms of motivation. Internal motivation. External motivation by application of force ("the stick"). External motivation by appli

There are perhaps three paradigms of motivation. Internal motivation. External motivation by application of force ("the stick"). External motivation by application of reward ("the carrot"). The most powerful motivation is internal, generally this is curiosity or mission-driven behavior for which the subject already has a mental or cultural configuration. To a certain extent, at the individual level if you need external motivation you have 'already lost' in that you will rarely be able to compete with internally motivated people in specialist endeavors. Therefore, the best method may be to help rediscover curiosity and interest through play.