An important debate could be based on this. Not only a debate,but a thesis can be arrived at starting from this contention -Nature vs Nurture.
As far as I’ve seen and analysed,people are groomed mainly based on the way they are nurtured in the circumstances they are exposed to.Their nature/hereditary traits/genetics does very little in shaping their personality. The qualities a person assimilates throughout his/her life is what gives a distinct meaning and purpose to that life. If the circumstances were any different,the person would be groomed in a totally different manner.
Parents play an important role;not by transferring their traits through the genes,but by selecting and/or influencing the circumstances their ward grows up in. This is the ultimate role of parents-To provide an ambience well suited for the nurturing of the child into a worthy person.
In Hereditary, or by nature,only physical qualities can be transferred and has nothing to do with the psychology of a human. So,ultimately nurturing is the winner,shaping the nature of a human.