i think that to some extent, yes, the way you are raised does have a bit of an effect on how you treat others, but it isn't everything. at the end of the day, you are your own person and whether you were treated right or not, you either act kind or not. we all have both light and dark inside of us, the part that really matters is how we choose to act on them, and that's who we really are. harry chooses to be kind and loving, because that is who he is as a person.