I could explain, but I am going to be lazy and cut and paste someone else's explanations-
My kids were given so much love and so many special things and opportunities, but I don't think extrinsic motivations are really all that good for people-
The problem with rewards and punishments (two sides of the same coin):
Danger to motivation for learning: Rewards and punishments are extrinsically rather than intrinsically motivated, meaning the child is behaving in a way so as to get a reward or to avoid punishment rather than for the sake of learning.
Danger to self-confidence: By using a controlling method to manage behaviour, you take away children's autonomy. Autonomy is a fundamental need which gives people the confidence to make decisions about their own lives. When taken away, it can have a negative impact on mental health.
Danger to self-esteem: Rewards and punishments are based on an adult's judgment of how good or bad a child's behaviour was. This can lead to the child thinking that another's opinion of them counts more than their own.
Danger to creativity & resilience: Rewards and punishments can make children fear making mistakes, so they are less likely to try something new.
Danger to self-regulation: When rewards and punishments are given out, Children are not taught to monitor and regulate their own behaviour, but rather come to believe this is the responsibility of an adult or other authority figure.
Danger to social & emotional intelligence: Rewards and punishments focus a child's mind on what will happen to THEM if they exhibit inconsiderate behaviour. If the reward or punishment is removed, how will that child choose to behave then? Surely, we should be teaching children that considerate behaviour requires thinking about OTHERS.
Danger to development of problem-solving skills: Our education goals are to teach children to problem-solve and think critically, but rewards and punishments teach them the opposite when it comes to behaviour – that they must obey, do as their told and not question it.
Danger to vulnerability: Rewards and punishments teach children to comply with directions given by an adult or figure of authority. This can make children more susceptible to abuse as they'll be less likely to protest or object to it when it comes from a person of authority.