Gould gives the history of IQ testing in a social and scientific context, exposing all the mistakes in the formulation and recognition of, for example, the factor g as a general, heritable, unique and unchangable measure of intelligence. He writes with ease and humour, and gives horrifying examples of rasism, sexism, misinterpretations and bad science. I always disliked IQ testing, and now I know why. If it is not done in view of helping those who have problems learning, it has a background of a multitude of social prejudices that we are still unwilling to acknowledge.