Oddly enough you will find many conservatives don't believe that and many liberals do.
However the liberals don't want that proper training to occur and fight tooth and nail to prevent it and conservatives do on the off chance there may be someone who can be helped.
That is why liberals are for schools that are little more then warehouses and conservatives are for vouchers so the ones who want to get a good education can get it.
It is not only culture but nutrition plays a big role in how a child develops.
some of the behaviors of ferals however, I think are simply genetic personality traits...the impulsiveness, the act first, think later, the constant egocentric thought patterns......I don't know how much of that one can be trained out of....