DRAMATIC DEATHS IN BUNCHES BREED CONCERN AND FEAR With scenes from the 2015 terrorist attacks in Paris, San Bernardino (California), and elsewhere flooding people’s minds, 27 percent of Americans identified terrorism as their biggest worry—up from 8 percent just before the Paris attacks (Reuters, 2015). The hijacking of our rationality by fears of terrorist guns (when other risks, such as driving or influenza, kill so many more) highlights an important piece of scientific news: We often fear the wrong things.

Christophe Petit Tesson/EPA/Newscom