On a breezy, crisp evening in December 2015, about 70 party-goers, some bedecked in feathers and glitter, entered the legendary Carwash disco in London’s West End. There they buckled packs containing accelerometers to their waists and danced for science. Daniel Margulies, a neuroscientist at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and his postdoctora...