Are we still committing Galton's error or is this just trying to ask whether creative is more learned or non-learned (I hesitate to say "genetic," as there are plenty of non-learned, non-genetic factors that can have an effect on human behavior)?
I would have to think it obvious that something like creativity cannot be entirely learned, as it seemingly has to depend heavily on the plasticity of the human brain, which is certainly an evolved, genetic trait. The level to which creativity can be learned would be extremely difficult to test for, however, given the many different variables that would go into it. You can't test it directly, as you can only test behavior, which would mean the expression of creativity. There are many traits that are not themselves creativity that contribute to the ability to express it: confidence, skill level, physical aptitude, cultural prohibitions/taboos, background knowledge, etc. I'd be inclined to think that all humans are pretty inherently creative, many, many times more than any other animal species. We all have the ability to do things like envision the future, imagine physically impossible occurences, and invent language. Nobody needs to learn how to do any of these things.
Are some more creative than others? Well, some certainly behave in more creative ways, and every human cognitive capacity has to be variable to some degree from person to person. No two humans have identical brains. The reasons each brain is different are manifold, with learning and hundreds of other factors each making a difference. Heck, it's entirely possible that some people are more creative than others because of genetics, some are more creative because of what their mothers ate while pregnant, and some are more creative because their parents made them solve block puzzles when they were toddlers. It could be different for each person.
