Fertility Ratio: Its Relationship to Mental Ability, School Achievement, and Race

Summary

This study related four 1970 U.S. Census variables—population, percent increase in population since 1960, percent nonwhite, and fertility ratio—to reading and arithmetic achievement and IQ for all 159 Georgia counties involving over 250,000 public school children in grades four, eight, and 12 in the Fall of 1971. Since the study used fertility ratio as defined by the U. S. Census (i.e., “number of children under five per 1000 women age 15 to 49”), the marital status of the parents, the legitimacy of children, and the number of childless marriages do not affect the actual fertility ratio of a county. The correlation between fertility ratio and mean IQ is negative for all three grades. Correlations range from —.43 to —.54; all are significant. This dysgenic trend is also seen in the rs between fertility ratio and reading and arithmetic achievement.