Spend enough time riding the New York City subway–or any big-city metro–and you’ll find yourself on the tenure-track to an honorary degree in transit psychology. The subway–which keeps random people together in a contained, observable setting–is a perfect rolling laboratory for the study of human behavior. As the sociologists M.L. Fried and V.J. De Fazio once noted, “The subway is one of the few places in a large urban center where all races and religions and most social classes are confronted with one another and the same situation.”
Or situations. The subway presents any number of discrete, and repeatable, moments of interaction, opportunities to test how “situational factors” affect outcomes. A pregnant woman appears: Who will give up his seat first? A blind man slips and falls. Who helps? Someone appears out of the blue and asks you to mail a letter. Will you? In all these scenarios much depends on the parties involved, their location on the train and the location of the train itself, and the number of other people present, among other variables. And rush-hour changes everything.