Variability Hypothesis - Leta Hollingworth's Studies

Leta Hollingworth's Studies

Hollingworth's position at the Clearing House for Mental Defectives allowed her the opportunity to refute the variability hypothesis. By examining the case records of 1,000 patients, Hollingworth determined that, although men outnumbered women in the clearing house, the ratio of men to women decreased with age. Hollingworth explained this to be the result of men facing greater societal expectations than women. Consequently, deficiencies in men were often detected at an earlier age, while similar deficiencies in women might not be detected because less was expected of them. Therefore, deficiencies in women would be required to be more pronounced than those in men in order to be detected at similar ages.

Hollingworth also attacked the variability hypothesis theoretically, criticizing the underlying logic of the hypothesis. Hollingworth argued that the variability hypothesis was flawed because: (1) it had not been empirically established that men were more anatomically variable than women, (2) even if greater anatomical variability in men were established this would not necessarily mean that men were also more variable in mental traits, (3) even if it were established that men were more variable in mental traits this would not automatically mean that men were innately more variable, (4) variability is not significant in and of itself, but rather depends on what the variability consists of, and (5) that any possible differences in variability between men and women must also be understood with reference to the fact that women lack the opportunity to achieve eminence because of their prescribed societal and cultural roles. Additionally, the argument that great variability automatically meant greater range was criticized by Hollingworth.

In an attempt to examine the validity of the variability hypothesis, while avoiding intervening social and cultural factors, Hollingworth gathered data on birth weight and length of 1,000 male and 1,000 female neonates. This research found virtually no difference in the variability of male and female infants, and it was concluded that if variability “favoured” any sex it was the female sex. Additionally, along with the anthropologist Robert Lowie Hollingworth published a review of literature from anatomical, physiological, and cross-cultural studies, in which no objective evidence was found to support the idea of innate female inferiority.

Hollingworth’s doctoral dissertation also dealt with the psychology of women. Entitled “Functional periodicity: An experimental study of the mental and motor abilities of women during menstruation” it found no evidence of changes in performance associated with phases of the menstrual cycle, refuting a common belief of the time. Interestingly, Hollingworth's graduate supervisor was E. L. Thorndike, himself a supporter of the variability hypothesis.