It's all too easy to become over confident, complacent. That's when something's most likely to go wrong. You're not alert. Making a Balanced Judgement whether or not to take the Risk Students talked about having consciously to make such decisions on those occasions where they were actually concerned about the risks involved, but felt the potential end-benefits of the proposed activity were appealing. However, the 'balancing' may not only use purely rational, factual criteria.
Perception is everything.
For example, a fairly hazardous activity may seem to be safe if everyone else is doing it. Alternatively, a tiny risk may cause undue concern because of the nature of the publicity that surrounds it. The BSE scare was taken as an example of this. Equally, the more one wants to pursue an activity the more one is likely to have an optimistic perception. Relying on the Judgement of Others Younger children in particular relied on their parents to judge whether an activity is sufficiently safe for them.