I have never been much of a daredevil or risk taker. Even as a child I didn't do risky/daring physical activities. Might be because my mom was pretty fearful of most everything and she did not instill much confidence in me. As an adult (I start biking and running at about 39) I have started taking more risks...but I'm also very cautious. If I am riding with my partner I feel much more comfortable riding on busy roads...I've done a lot of rode (some time busy roads) riding so I probable feel comfortable because of my experience and again better with my partner. I do NOT like descending at all. I think this is again a confidence issue, I often visualize my crashes (seriously!). I also have crashed going downhill, so definitely adds to my fear. But I think it is the fact I don't feel comfortable with my skills. Running is probably less of a risk...usual car vs pedestrian stuff but overall I probably don't take risks. That being said I have done Pikes Peak Ascent twice. First time I did pretty good for a flatlander, second time bad altitude effects and I almost didn't make the cut off. I hope to go back this year, but now that I tasted failure (well almost failure) I am more afraid of not only failure but that I might actually die. (OK maybe I'm a bit dramatic but people can die doing this!).
So I guess I have never been a risk taker (I would not ski downhill--scary!), but I think it may be more related to lack of confidence in my physical ability than my age. As I have gotten older I probably have been involved in things that are more of a physical risk than my younger years!
K