Interesting debate. On the topic of how children view the safety / danger aspect of cycling, my eight year old son and I watched an episode of Top Gear (which we both love) a few weeks ago, where there were several spoof adverts which paraphrased "I earn money, I bought a car. Don't cycle, cos you'll die".
I just thought it was a bit of humour until last week when my son suggested to me that I should drive to work, because I could afford to. If I cycled "I would probably be killed". Thanks, Clarkson...
Back to the helmet (and the helmet wars debate), I am pro-choice in pretty much all of its forms. My choice, however is that me and my family will wear a helmet because I would prefer to have 2" of polystyrene between my, my wife's or my son's head and the concrete or a car, should contact occur.