The experience stuck with McNeill, and after the war, when he became a professional historian, he returned to the idea in a monograph called Keeping Together in Time. In it, he argues that synchronised movement, along with synchronised singing, has been a vastly underappreciated force in world history, fostering cohesion among groups as diverse as the builders of the pyramids, the armies of the Ottoman Empire, and the Japanese office workers who rise from their desks to perform group calisthenics at the start of each workday.
