A Brief History of Everyone Who Ever Lived: The Human Story Retold Through Our Genes

by Adam Rutherford

The Forer effect is a psychological phenomenon where people conclude that broadly true statements are accurate for themselves personally, when they are in fact generically true for many people. In 1948, psychologist Bertram Forer gave his students a personality test, and followed each one with a bespoke vignette of their character. They were then asked to rate their personalized analysis, which they did very positively—an average of 4.26 out of 5. Except they weren’t personalized at all. All the personality sketches were identical, made up of thirteen bland statements that vaguely describe common or desirable personality traits: At times you are extroverted, affable, sociable, while at other times you are introverted, wary, reserved. This is how astrology works—divination drawn from banality, that we are complicit in. We cling to the things that appeal, and happily ignore the rest.