Why are the westerners so adventurous?

It is true that the westerners, especially the Americans are fond of adventure. Before I got into touch with them I just thought those were only  the images in the TV plays and novels. But my personal experience proves that this is real. Nearly each time I went to the moon hill or just on the way to the moon hill in Yangshuo we could see lots of Americans or Europeans do rock-climbing. Lots of we Chinese would stop to take pictures. While watching them doing that dangerous yet exciting exercise, our topic is always concentrated on the reasons. Why? Why those people would choose to take that adventure while they could make much more leisure and safer choices? And also why these people would risk their life for a game that could only bring them dangers and worries? I know their answers would always be that from that exercise they could get excitement and satisfaction or that Guilin is so perfect a place for rock-climbing etc. But are there any other reasons apart from these? I mean are there any deep-rooted reasons from the education or history or something?? Really want to know more about this. Thank you.
Hope that I could see you from those climbers in Yangshuo.

I have see for many times that lots of people doing the rocking climbing in Yangshuo.