An example of an independent variable in psychology: In an experiment on the impact of sleep deprivation on test performance, sleep deprivation would be the independent variable.

This “potentially causal variable” is called, traditionally, the “independent variable.” With the current example, that would be the coffee.

Christopher H. Achen, Social Psychology, Demographic Variables, and Linear Regression: Breaking the Iron Triangle in Voting Research, Political Behavior, Vol. 14, No ...