The Tyranny of the Normal Curve: How the “Bell Curve” Corrupts Educational Research and Practice

Abstract

The idea that human behavior distributes more or less “normally” along the lines of a bell-shaped curve has achieved the level of common sense. However, only random events distribute normally, and the behavior of human beings is never truly random. The normal curve—as applied to human behavior, traits, and abilities of humans—is a myth, an example of scientific groupthink that distorts the meaning of educational research, leading to practices that fail to meet the needs of individuals or subgroups of students whose profiles depart from group norms. The antidote to the “tyranny of the normal curve” is for educators to shift their gaze from measures of normative tendencies to measures of variance.