From my perspective, when the child works on, which I think is good, get a lot of good things for him: self-confidence, because its advance only owes itself develops skills: creativity, autonomy, have control of their work, working on what he likes, what he wants, growing interest, motivation, work provides quality relationships with those around you, without manipulation, without competition.
Those are the positive reinforcement, natural, real, intrinsic, which will motivate the child to continue to grow, working, learning, and