But we must not forget that woman are, on the average, a little less intelligent than men, a difference which we should not exaggerate but which is, nonetheless, real. We are therefore permitted to suppose that the relatively small size of the female brain depends in part upon her physical inferiority and in part upon her intellectual inferiority.
Paul Broca 1824-1880
Back in the mid 1800’s there lived a professor named Paul Broca. His work on the brain was instrumental in brain anatomy and anthropology. He determined the part of the brain associated with speech, revolutionizing our understanding of human speech. His work was thorough, and he was ahead of the times in his scientific thinking. However, even the best scientists can be influenced by social bias.
Paul Broca performed measurements of cranial sizes of male and female skulls, and found that the female cranial size was smaller. Was the measurement correct? Well, to a certain extent, yes. Yet, the problem with the study was his conclusion. A great summary of some of Broca’s study can be found in this essay by Stephen Jay Gould (PDF). The issue is that there are numerous factors that may lead to intelligence, and not all are linked to brain size. In fact, with newer technology, we have also found that it is neural connections within the brain which make a great contribution to intelligence.
Female Brains Are Still Smaller
Now, the time of Paul Broca was very different from modern day. You would think something like using brain size to prove women are less intelligent would be a thing of the past. Not necessarily. A study from 2006 by Philippe Rushton claimed that men were on average smarter than women due to brain size. This debate was still going on in 2006.
This same author published a paper in 2002 citing differences in brain size in different races are what cause the IQ differences. The paper, called “Brain size, IQ, and racial-group differences: Evidence from musculoskeletal traits,” in which the concluding sentence of the abstract states “brain size-related variables provide the most likely biological mediators of the race differences in intelligence.” [Rushton, 2002].
When coming to scientific conclusions, it is important to remember that correlation does not imply causation.
The ultimate problem with studies like these is that they completely disregard cultural and societal contributions to intelligence. For instance, we are just now coming into a time where more women are applying to college than men, and more equal opportunities are available to minorities and women.
To end, I leave you with the most recent tidbit of information I could find. For the first time in recent history, women are scoring higher on IQ tests than men.
So much for that publication citing the reason for women’s lower IQ scores was due to their brain size.