It’s possible but I don’t really buy it. There’s a very real sense in which narcissism is just a lack of acquired skills that most people have. That skill being the ability to see both the good things and the bad things about yourself and about others at the same time. If you’re raised in an environment where your caretaker teaches you they are always right (with severe consequences for pointing out they aren’t) then it is hard to develop a nuanced worldview. The child can either get on board with the parent, become “one of the good ones” and become a narcissist themselves or they can become a black sheep of the family, usually with worse outcomes.

Importantly, the skills can be learned as an adult it’s just hard to do. I come from a long lineage of family members who did not know how to swim, but I don’t think that there’s a genetic basis for this.

You hit it on the nail head with lack of coping skills. I had a grandmother who tried to compensate for the way my mother treated me by treating me like I was royalty. And my coping mechanism for being treated poorly at home was thinking that I was better than everybody else in some way. Combine those two with the fact that I was taught no coping skills, and yes I became a narcissist.

When I had my awakening, I was finally able to put to work some coping skills I learned the hard way, in a mental hospital. But once I realized the problem was me, the changes were instant. I was ready for change.

Unfortunately, some people have no such awakening. And I avoid those types of people like the plague.

I think genetics are completely misunderstood. I also have serious Narcissism in my family and to me it very much looks like that's the world view you learn if that's how it's demonstrated to you as a small child. Small children have no filter on inputs also. If dad isn't around because mother is unbearable and she lives a narcissistic reality it becomes the water that you swim in. I don't think there is genetic code that determines that you think other people are to blame for everything!

Random theory: Children of narcissists like IT because it's a world that is very predictable with rational explanations.

or it could be a biological disposition to developing it as a response to the trauma of being raised by a narcissist

I've come to believe that a deep childhood wound (parental divorce, neglect, abuse, or being adopted, etc.) predisposes one to become a narcissist when combined with the message that you are special, different from others, etc.

Steve Jobs, for example. He wasn't as malevolent as Donald Trump, but both have both factors: the childhood trauma + the message that they were special. I have several acquaintances who are narcissists and have both factors as well.

I think that the trauma without the message that you are special and different predisposes someone to become a hyper-achiever, where ambition is a channel for the pain. See: Elon Musk, Tim Ferris, etc.

   I've come to believe that a deep childhood wound (parental divorce, neglect, abuse, or being adopted, etc.) predisposes one to become a narcissist when combined with the message that you are special, different from others, etc.

You just described my childhood.