Twins: Black and White

"The study brings together for the first time in one volume an analysis of psychological test results and biometric measurements of large samples of black and white twins—in all, 496 pairs of twins, ranging in age from 12 to 20. In addition to the heritability estimates reported previously (Osborne, 1978), important new analyses of personality, socio-economic status, culture fair and primary mental ability tests, and neurological findings are presented.
In the body of the survey, the reader will find independent chapters dealing with heritability of mental ability, school achievement, and personality by race and by sex. In the appendixes will be found all raw data, including psychological test results and the biometric measurements used in zygosity determination. From the printouts in the appendixes, studies in the body of the text may be verified or unreported relationships among the variables may be investigated. Tapes of the appendixes are available from the author."