Islam talked about Fitrah (instinct) that leads to Tawhid (doctrine of Oneness of God) in the absence of external obstacles.
As for heredity (genetics), it represents the preparations that govern the soul if left in its natural course, but the external factors, the parenting style and experience, interfere in the formation of the personality, so it weakens the influence of heredity, limits it, and does not allow it to control all the consciousness of the human, the mental and emotional ones. Thus, those preparations do not appear but only in case this conscience becomes weak every now and then.
Hence, I say that the way by which you raise kids suppress heredity, but I am not saying that it completely abolish it. It only prevents its mobility in one’s soul, except in the presence of weakness, which controls humans from time to time.
On the other hand, I do not imagine that the nature predominantly overcomes nurture, but the nurture if it was subject to a long contractual plan, it creates a second nature. In this case it would not be nurture, but would turn into a new nature that removes the original nature and replaces it or covers it in a way that makes that old nature lacking any effect on the personality.
We understand from this saying: “Bred in the bone will come out in the flesh”, and from other similar sayings, as: “…For the maternal uncle is one of the two pillars (the largest trainer) your offspring…”, that heredity has a big role in giving natural capabilities that might get a child ready, positively or negatively, but it neither paralyzes his/her action, nor abolishes the role of the parenting style, which is supposed to absorb these capabilities.
In response to the opinion, which says that the heredity traits represent an excuse for a human being that would save him from God’s punishment in the event of his/her failure to comply with His orders and prohibitions, we say that we must notice this issue i.e. the size of the parenting style used and its strength. If the parenting style was adopting a normal approach that depends on the type of shallow effects, such as the methods of counsel, advice and social conditions, then the nature of the heredity in this case would overcome the parenting style. This is what we see among many of those who live religion in a superficial way; once they are present in an environment that is consistent with their inherited tendencies to decompose the religious commitment those tendencies overwhelm, arise, and significantly affect them.
If we assume that the parenting style have had a profound influence in the soul, then it would be very difficult to remove it. For example, we find that the parenting style in many cases overcomes the environment, as we find that the environment often stands as a barrier in front of the strong effect of the parenting style.
As a conclusion, heredity is not a unilateral factor controlling the formulation of the human personality, as fate and destiny, but it is rather one part of the total internal and external factors that interfere in the formation of the personality of any individual. Here, the heredity factor might overcome other factors when being strong, otherwise it might not…