Years ago, while doing research for a book on risk-taking (Chancing It: Why We Take Risks), I interviewed lots of skydivers, rock climbers and the wire walker Philippe Petit. Even though such activities have caused countless fatalities, all told me they were sure they wouldn't be one. Why? "Because I'm good at it." The implication was that others – especially those who died – were not. This has some bearing on the otherwise intelligent people who continue to talk on cell phones while...