To decide which of the two- nature and nurture- is of more importance is a difficult thing indeed, seeing as it sets the Id and Superego of the human race as rivals. The Superego is everything we have been taught how to do- the “right and wrong” things that society has pounded into our brains so that they feel almost instinctive, when it’s not; things like picking the one we’d like to marry based on their looks or deciding not to steal candy from a store because it isn’t morally “right”. The Superego has taught humans to love and care, which includes taking care of the ones they love with more care than necessary for survival, a.k.a. spoiling children. (Humans are some of the only creatures that require such a long period of time for full development). The Id- (nature) the bare, animalistic instincts at the core of each individual such as the need for food and reproduction that make all living things get what they want/need immediately- is, naturally, the more aggressive/possessive of the two, because it gets a person whatever they want when they want it, and said person will do anything to get it. In a strictly survival-instincts-or-die situation, the Id takes control over the human body and mind, making one become seemingly harsh and hostile.
Take Rasheed, for example. Although he abides by his society’s laws, his Id rules over his brain when he’s not in public. When he comes home, his wants and needs- food, sex, etc. - take over, especially when Mariam or Laila upsets him, in which case he does his best to snuff out the problem with a good beating, just the way an animal would.
Mariam, on the other hand, has a nice mixture of both, seeing as she does exactly what she needs to survive, but yearns the affection from a few others while lovingly tending to Aziza and Laila. As she grew up, Mariam had to deal with more and more- losing Nana, marrying Rasheed, etc. – that made her exterior hard and nearly impenetrable, thanks to