Almost for sure our parents are the best teachers at the beginning of our lives, which actually corresponds to the parents' role in nature. Parents are most committed and involved in teaching their children; they have a kind of instinct to sacrifice a part of themselves for the betterment of their children. They love us and have great patience while passing down their knowledge to us. They wish us a success and thus will not teach us bad things. And of course, implicit learning occurs when children unconsciously copy some of their parents' habits and styles of behavior.
During the second stage of child development, adolescence, parents can still be in the best position to offer advice even though the children might not accept it. In this case, perhaps the child's friends would be the best teachers. Adolescents are notoriously rebellious in many cultures and may automatically reject any advice from their parents. My first marriage for instance, was solely a matter of doing the opposite when my parents tried to intrude in offering their advice. So in such matters, parents should be much more flexible and be rather the partners with their children. So we can see that being a teacher of growing child become more and more complicated case as the time passes and many parents are simply not able to meet the increased demands.
On the other hand, I would say that parents are not professional teachers and they tend to be very biased by their love of their children. So wishing good things and an easy life may prevent children from maturation. In any case, parents usually can present only one viewpoint of the world, while good teaching should be based on different attitudes. Thus, when children go to school and have a great diversity of teachers, they learn much more than their parents could probably give them. Furthermore, once our parents get older, they become more conservative and cannot always be objective in regard to modern trends and fashions. Thus we need to take their advice with caution during that period. However, some kind of intuition which I believe shared between relatives about what everybody needs and great love which exists in a families still makes our parents very good teachers and advisers at any time
(Source: Test Magic)