The idea of being attacked by a shark, as unlikely as it is, is scary. But why, if the odds are so low? Because our perception of risk is not just about the numbers. It's about emotions too. There is no better example of how risk perception is more a matter of emotion than of quantitative reasoning than this classic illustration of how our fears sometimes don't match the facts.
For decades the common wisdom of parenting manuals was that teenagers feel invulnerable, immortal, and simply perceive less peril in dicey situations and believe they have much more control than they actually do. In short, they underestimate life's very real risks and dangers. But scientists who study adolescent decision making now dispute this common parenting wisdom.
Hopefully one of the outcomes of this recent Disneyland measles outbreak will be more research to confirm the underlying psychological drivers of Vax-O-Noia. Unless we understand the root cause of this persistent threat to public health and apply that understanding to the task of addressing people's fears, episodes like the current outbreak will continue to occur