Some parents may be proficient and experienced freethinkers, and may never personally experience the terrible consequences of this egotism of theirs. However, children cannot always echo their parents. Rather than be poor copies of their parents, children will often try the only alternative. Thus, if the parents are freethinkers, the children may well abandon thought altogether and become fundamentalists.
Confused, the parents will plea, "We didn't bring our children up to be that way." Then I ask, who did? The children are egotists just like the parents. The particular "drugs" they use may not be exactly the same, but this is a trivial matter, as all such drugs are interchangeable and equally destructive.
So you see, the two poles of thinking are inseparably joined. One comes with the other, leads to the other, and there is no escaping it. The more stsrongly one encompasses free thinking, the more certain is the result of fundamentalism - and the more strongly one binds oneself to the ego-cycle of samsara.
How to escape the double bind? Become a real freethinker. Real freethinkers have no attachments.