The famous mathematical sociologist Paul Lazarfeld once said, “You never understand a phenomenon unless you can make it go away.” We might add, “or unless you can reverse its direction.”
Psychologist William McGuire (1983, 1989) suggested as one of many ways to develop new hypotheses that you can take some seemingly obvious relationship and imagine conditions where its opposite would hold.
Robert P. Abelson (1995). Statistics as Principled Argument