I believe our; childhood, parenting, schooling, religion (influenced upon us by parents, etc.), living conditions, experiences and so forth, all play a part in our future decision making process, along with out behavior.
Most ppl stick to all that and live by it.
Some however, are able to change, evolve so to speak, depending on new experiences and views of life itself.
But in conclusion, I honestly believe you own your own behavior and should be able to choose how you are.
Sadly some ppl are born with mental/physical problems, I'm not counting them into the mix. A lower IQ example, you've been born this way can't do much to change it.