Variability Hypothesis - Early Acceptance

Early Acceptance

Later that century the character of the variability hypothesis was altered to coincide better with Charles Darwin's emphasis on the importance of variation from the average for the evolutionary process. Following Darwin, the variability hypothesis was instead put forward as man's greater variability compared to women, and its application was soon extended to sex differences in mental abilities. Thus, men were thought to vary greatly in their abilities, while women were assumed to be basically the same in their abilities. The greater number of men at both ends of the intellectual spectrum (as patients in institutions and as great intellectual achievers) was taken as evidence of man's greater innate variability.

In the early twentieth century, the variability hypothesis flourished in sociological, psychological, medical and educational literature. The hypothesis received support not from empirical evidence, but rather from "armchair dogma" about innate female inferiority. Among the proponents of the variability hypothesis at this time were psychologists G. Stanley Hall, Edward Lee Thorndike, and James McKeen Cattell. One logical conclusion drawn from the variability hypothesis was that since women were not expected to exhibit above-average intelligence, it was unreasonable to expect eminence from them. This led Thorndike and Hall to suggest the adoption of curricula aimed at preparing women for their future roles as mothers and wives. The only significant critic of the variability hypothesis was Karl Pearson, a British psychologist who had studied variability in 1897 and found no sex differences. Pearson's research was the only published scientific investigation of the variability hypothesis prior to the work of American psychologist Leta Hollingworth.