Parents expect way too much from their kids.

Alan Kazdin:

Because parents love their children and want the best for them, they worry about them a lot, and one of the things that parents worry about most is whether their children are hitting age-appropriate targets for behavior. Shouldn’t a child be toilet trained by the age of 4? Should a 10-year-old to be able to sit down and do an hour of homework? One reason why such questions produce so much conflict and woe in the home is that parents’ expectations for their children’s behavior tend to be too high. I’m not talking about permissiveness or strictness here; I’m talking about accurately estimating children’s actual abilities. A reliable body of research shows that we expect our children to do things they’re not yet able to do and that we judge and punish them according to that expectation.