How might the different theories of motivation explain why some people engage in high-risk behavior such as skydiving, stock-car racing, and bungee jumping while other people prefer to avoid any potentially dangerous situations?

It's rather psychological question. People often pre-judge about extreme actions in this case high-risk behaviour, based on their personal experience ... And because of the basis of pre-judgement that they made almost never changes in extreme cases unless some kind of a drastic change in their life appears, they will keep telling themselves whenever they will be asked about it and therefore they will avoid it.