Intelligence quotient, as a useful means of measuring brain capacity, has come increasingly into the public eye in recent years.

This famous book (and its sequel "Check Your Own IQ") enables the reader to estimate and confirm their own IQ rating. In the first part the well-known author of Sense and Nonsense in Psychology and Uses and Abuses of Psychology describes clear what an I.Q. is, how it can be applied and what the shortcomings of this system of rating may be.