[Kamq]

The thing that immediately pops into mind is that learning to be careful when there's a moderate risk of injury makes people better at finding the limits in dangerous activities that they'll face later in life without going too far.

This is assuming that being careful and finding the limits of a dangerous activity without being injured is a skill that needs practice, but that doesn't seem like too much of a stretch.

You could test this by seeing if kids who had trampoline enclosures were less likely to hurt themselves seriously as an adult.