This "psychological size" differential exists not only because children see their parents as bigger and stonger, but also as more knowledgeable, more competent. To the young child there seems to be nothing her parents to not know, nothing they cannot do. She marvels at the breadth of their understanding, the accuracy of their predictions, the wisdom of their judgement.
While some of these perceptions may at times be accurate, others are not. Children attribute many traits, characteristics and capabilities to their parents that are not based on reality at all. Few parents know as much as young children think they do. Experience is not always the "best teacher," as the child will later conclude when she becomes an adolescent and an adult and can judge her parents against a broader base of her own experience. And wisdom is not always related to age. Many parents find it difficult to admit, but those who are more honest with themselves recognize how exaggerated are children's evaluations of Mom and Dad.
While the cards are stacked in favor of the parents' far greater psychological size to begin with, many mothers and fathers foster the difference. They deliberately hide their limitations and mistakes in judgement from their children; or they promote myths as "We know what's best for you" or "When you're older you'll realize how right we were."
I've always been intrigued to observe that when parents talk about their own mothers and fathers, they readily see in retrospect their mistakes and limitations; yet they will strongly resist the notion that they are subject to the same kinds of errors of judgement and lack of wisdom in relation to their own children.
-Dr. Thomas Gordon