I believe in nature and its wonderful effects over our interraction in the society but I also believe in influence. I believe in knowledge and what it does to person behaviour.
A child's behaviour depends on his parents behaviour, their behaviour toward each other.
bad behaviour
Children watch their parents so closely that their behaviour becomes a second-nature to them. So they behave and talk like their parents and everybody will say it's a nature, that your child has to have your behavioural traits.
What if the children grew up with another family?
Definitely they will adopt the pattern of the other and would not look like their real parents behavioural-wise.
Physical look is nature. You might look like your dad, mom or both. But behaviour and mindset is constructed in the outer world, based on experience and exposure.
This also applies for whether a child is going to live a the good or bad life...
The level of their goodness or badness deeply depends on their level of exposure to either the good or bad.
But one thing is certain, a child makes wise choices when he's been offered to.
good behaviour
Instead of restraining a child from doing what he feels is right or keeping him in the dark about good/bad knowledge, he should be allowed to know or even experience everything, letting him know the consequence of the good, bad or the ugly.
That's adult mindset!
The fear of the consequences of our actions always keeps us on the right side, making us to make good choices.
So it depends on parenting, the kind of knowledge a child is fed on. Nature has small to do with our behavours!