How to Lie with Statistics

by Darrell Huff

The crooks already know these tricks; honest men must learn them in self-defense.

When you are told that something is an average you still don’t know very much about it unless you can find out which of the common kinds of average it is—mean, median, or mode.

Only when there is a substantial number of trials involved is the law of averages a useful description or prediction.

Just to clear the air, let’s note first of all that whatever an intelligence test measures it is not quite the same thing as we usually mean by intelligence. It neglects such important things as leadership and creative imagination. It takes no account of social judgment or musical or artistic or other aptitudes, to say nothing of such personality matters as diligence and emotional balance.

The point is that when there are many reasonable explanations you are hardly entitled to pick one that suits your taste and insist on it. But many people do.

There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.