Emily Balcetis: One reason people are so desperate for masks is that in times of heightened stress people tend to resort to “magical thinking” and superstitious behavior — particularly when there seem to be few ways to exert control over a situation. The first line of psychological defense in a crisis is often denial. But as evidence of the disease’s scope grows, documented by dire news reports, denial becomes implausible. That leaves another comforting option: clinging to the belief that one can ward off undesired outcomes by engaging in behaviors that bear little to no relationship to accepted laws of science and nature.