In "Blank State," Dr. Pinker describes our evolutionary genetics for this matter.

He says our hunter-gatherer ancestors who stayed with the "known ways" passed their risk averse genes down. Those who experimented got weeded out.

About 1800, it became safer to try out some new ways. No longer was it as dangerous to partake in many life activities. What happened is that we reduced the risk of new ways, say, from 30% to 0.30%. Our hunter gatherer brains seem to think that 0.30% is zero. This helps speeding drivers justify speeding because they speeded the last 118 times they made the trip from Point A to Point B. Reducing the risk from 0.30% to 0.03% is quite significant to some of us, but not to many. The many are more influenced by speeding tickets.

As for the factory disaster, there's a whole whack of psychological reasons when we cannot collectively make the right decision. The BP Macondo blowout was another good example of that. In the future, I hope a well trained psychologist becomes part of these engineering teams.