It’s really both. Obviously genetics plays a key role in our physical development, but many environmental factors — both physical and social — come into play in shaping us as we develop. It’s a complex process. I’ve had a lifelong interest in astronomy, for example, which I’m pretty sure was instilled in me and nurtured by my father, who also had an interest in the subject. I wasn’t born with that interest. But I suspect I was born with a reasonably analytic bent, which makes me good at things like physical sciences, math, and (as it turned out) software development. I’ve acquired some facility with words, but my wife is far more a “words person” than I am. She was reading at a sixth grade level in first grade. She largely taught me how to write, and she still is indispensable to me as an editor and general sounding board for my stories. But she and math (and sometimes computers) just don’t get along!