I would say that some of the spacial reasoning ability is innate to a person, and will determine how easy it is for the person to learn to solve physical proble

I would say that some of the spacial reasoning ability is innate to a person, and will determine how easy it is for the person to learn to solve physical problems. Past this, a lot of the ability comes from having seen similar concepts before and being able to create an elegant solution from them. When I solve problems like this I typically get a vague sort of vision of what the final solution is going to look like in my head (possibly the innate part). Then I take all the little things I know about and slowly build up something that will perform the action I want. After which it becomes a task of optimization by combining and changing things until the final solution falls out (the experience part). When you have 2 or 3 people working on the same problem using this process some really special things often come out of it.