Intelligence tests are not perfect. They still measure potential inaccurately in the culturally deprived, or in those from cultures different from that in which the test was standardized, but they are less unfair than anything else. They are only a rough guide, but many experiments have shown that they are better than, and less biased than, unaided human judgment. They are better than guesswork, more efficient than trial and error, and they are improving all the time. They were invented as an instrument of social justice, a way of penetrating to the central capacity of a person despite his lack of education.
This book is written to amuse and instruct. I do not claim the tests within it will tell you exactly who and what you are. They are a good example of the kind of thing you will meet if ever you are seriously inclined to know yourself.