What are the two factors that define our traits?

There are a few theories as to what defines our traits to create our personality

According to one such theory, Dan P. McAdams claims our personalities develop in three stages:

Our genes cause genetic mutations forming a 'draft' personality. During our early upbringing, our parents, teachers and friends treat us differently based on our looks and draft personality. Once we are older we then form a narrative of our lives based on our experiences growing up, and make decisions consistent with the character we have created.

So our traits started from slight genetic variances, which effected how we were treated, which then shapes our own self-narrative. So really, our personality is one big story that we tell ourselves, and our childhood was the prologue to that story.