In this study the pattern of temporal variation in innovation rates is examined in the context of Western IQ measures in which historical genotypic gains and losses along with the Flynn effect are considered. It is found that two alternative genotypic IQ estimates based on an increase in IQ from 1455 to 1850 followed by a decrease from 1850 to the…

Using data for 4,316 men and 4,782 women--from the 1975 Wisconsin Longitudinal Study of Social and Psychological Factors in Educational and Occupational Aspirations and Achievement--the relationship between intelligence quotient (IQ) and fertility was assessed. The effect of education on family size predicts the direction of evolution of genotypic…

Genetic and environmental etiologies of individual differences in tests of intelligence and school achievement were investigated in a study from the Colorado Adoption Project. A multivariate conditional path model was fitted to general cognitive ability and reading performance data from 119 adoptive and 120 nonadoptive families. (SLD)