Richard Lynn, one of the leading researchers on intelligence and personality and the author of several major books on IQ and personality research, summarizes in this landmark work what one scholar has described as “the definitive study of race differences in intelligence.” Since 1977, Richard Lynn has blazed a pioneering trail of research on racial differences in IQ. In previous books and scientific articles, Lynn has explored dysgenic trends in intelligence, sex differences in IQ, psychopathic personality traits, and the dimensions of personality and national character.

In this book, Lynn analyses the results of over 500 published studies that span ten population groups—races and sub-races worldwide—in what is certain to be a path-breaking book for IQ experts and educated laypersons alike. This comprehensive review of worldwide racial differences of general intelligence explores the formation of races, meaning of intelligence, validity of race differences in IQ, environmental and genetic correlates of intelligence, the relationship between brain size and intelligence, the evolution of racial differences in intelligence, and the factor of racial hybrids. In a relentlessly methodical approach, Lynn expands upon an extensive array of research findings from the biomedical and social sciences, including the latest studies from the fields of behaviour genetics, evolutionary psychology, and anthropology in reaching his thought-provoking conclusions. Extensively referenced, this exhaustive study of race and IQ is a milestone accomplishment and should serve as the yardstick by which future research is measured.

"The IQs of the races…can be explained as having arisen from the different environments in which they evolved, and in particular from the ice ages in the northern hemisphere exerting selection pressures for greater intelligence for survival during cold winters; and in addition from the appearance of mutations for higher intelligence appearing in the races with the larger populations and under the greatest cold stress. The IQ differences between the races explain the differences in achievement in making the Neolithic transition from hunter-gathering to settled agriculture, the building of early civilizations, and the development of mature civilizations during the last two thousand years. The position of environmentalists that over the course of some 100,000 years peoples separated by geographical barriers in different parts of the world evolved into ten different races with pronounced genetic differences in morphology, blood groups, and the incidence of genetic diseases, and yet have identical genotypes for intelligence, is so improbable that those who advance it must either be totally ignorant of the basic principles of evolutionary biology or else have a political agenda to deny the importance of race. Or both."

 

Lynn's central finding: the world average IQ is no more than 90, and declines from north to south.