From what I understand, it is genetic and environmental factors that helps to develop our personalities. That’s pretty much a basic concept. Some theories talk about our personalities are developed in different stages. I think Freud had stages of Psychosexual development. Jung thought that your personality had a developmental process that went through a person’s life.
There are plenty of theories on this topic.
I am very much in the earthly science camp. That does not mean there is no religious component to it either. After all, we are God’s creation therefore at the most fundamental level we are in nature as He made us to be. We have fallen, true enough, but that did not eradicate ALL of His intent for our being.
God is not necessary to produce individual personality, IMHO.
I disagree. While God, in the sense we as Catholics know Him, may not be necessary per say, every culture and, by extension every human has to come to terms with spirituality. Even if that resolution is to reject outright or to superficially brush it off (still a chosen coping mechanism), the question needs to be dealt with. Once determined, that answer joins the “nurture” influences on personality.
So, while God, now speaking in the Catholic sense of Him, is necessary to produce any given individual’s personality 1) for being author of all potential personality building prerequisites (genetics, all of creation, etc. to which I add our souls), and 2) personality will absolutely be affected depending on the level of presence or absence we allow God. Moreover, regardless of our choice described above, all still have a soul and all, consciously aware of it or not, remain influenced by the Holy Spirit in some form.
There are a lot of grey areas in the study of personality, and there’s a lot of fishing that goes on in hope of a quick publication, but IQ is generally viewed as a trait.
Yes, if you buy into earthly science. But what about religion?
IQ is part of a person’s personality, true. However, in that it really is no different than any other “nature” contributor. It is part of the bedrock the nurture components build on. It plays an immensely important role but, at the end of the day, it is just another ingredient in the personality stew.
Part of the problem, as I see it, is we tend to seek unified theories for everything. Unfortunately, that typically is not how most things work. This is a fundamental tenant of systems of engineering: when dealing with a system of systems, each individual part has the potential to behave in unique ways once integrated that it would not otherwise display when operating independently.
In the psychology world Gestalt Theory best addressed this: “The whole is other than the sum of the parts (K. Koffka).” The parts, in humanity include nature (genetics, IQ, temperament, physical weaknesses and strengths, etc.), nurture (parenting, culture, environment, etc.) and the neglected but so very important spiritual (God created us in Him image, endowed us with a soul, and placed us ever under the influence of the Holy Spirit).
and at the same time 
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