What Is Intelligence? Beyond The Flynn Effect

The Flynn Effect refers to data the author studied indicating massive IQ gains in the developed world during the 20th century. Now Flynn speculates on the cause for these apparent gains. His answer centers on the replacement of concrete, experience-based thinking by abstract scientific thinking. Citing many scholarly works, Flynn paints a dynamic picture of what intelligence is and the role of a person's genetic background, physiology and neurology, immediate environment and broader social factors. He notes, for instance, that an individual's small genetic advantage can be multiplied greatly by environmental forces. An important chapter looks at a fatal consequence of IQ inflation: the use of outdated IQ tests and norms could lead to the execution of someone convicted of a capital crime who by today's standards is mentally disabled.