Elizabeth Landau: “Otherwise reasonable people enact all kinds of rituals to promote good luck or cast off the bad, especially in situations of uncertainty. Three different Facebook friends of mine say they touch the outsides of the airplanes they are boarding before takeoff. Chimney sweeps are considered good luck in Germany, and another former colleague of mine would try to touch them when she was a girl growing up there.” What’s behind this is something called “embodied cognition.”