9.2 Gender

Measuring Gender Differences (and Similarities)

People are fascinated with gender differences. When a new baby arrives, the first question is often “Is it a boy or girl.” Many studies have been conducted and observations made to look at the differences between males and females. It is important to consider how we measure those differences when taking a scientific approach to the study of gender differences. This can be a daunting task since there is no single type of test used in investigating gender differences and cognition. How do we compare across findings from SAT scores and grade point averages where we get very different pictures of how males and females perform in mathematics? On the math SAT, males typically perform females by about 32 points, but in the classroom, females earn higher math grades on a five point scale. These scales are quite different. We could compare the percentages of maximum score on each measure. Using that approach, you would say that males outperform females by 3% on the math SAT. Then you can make a judgement about whether a 3% or a 10% difference is scores is meaningful.

A more scientific approach is to investigate effect sizes. Comparing effect sizes is a typical approach in a meta-analysis review of many articles. An effect size is calculated using the means of the two groups you are comparing on a measure and the standard deviation for the scores on that measure. You then subtract the difference between the means of the two groups and divide by the standard deviation. This gives us an indication of how the average of one group differs from the average of the other group. An effect size of one would indicate a substantial group difference of one standard deviation. An effect size of zero would indicate no difference at all in terms of means or how the scores are distributed. An effect size of .20 is considered a small effect, a moderate effect size is .50, and a .80 is a large effect (Cohen, 1988).

Gender differences in Academic and Cognitive Performance

There are inconsistent findings regarding gender differences in academic performance. Byrnes (2001) summarized these findings. In reading for the early grades, small effects showing a female advantage. The small advantage for female reading scores were also evident in the 1990 and 1998 National Assessment of Educational Progress (NAEP). For many years, females scored higher on the verbal part of the SAT, but in recent years, this advantage has disappeared. The findings showing females score higher on measures of writing are more consistent (Byrnes, 2001). Voyer and Voyer’s (2014) meta-analysis showed that females perform better on school grades overall than males. They found these differences greatest for language-related courses. They also noted that many other factors were important moderators of the effect sizes.

Gender differences in mathematics are not found in preadolescence. Findings are less consistent when studying adolescents. One standardized exams, such as the SAT, there is a male advantage. This effect size is of moderate size. In contrast, low to moderate effects show females performance in school results in higher math grades (Kimball, 1989).

Gender differences are evident in some specific cognitive tasks. One task showing a moderate effect of male superiority is the mental rotation spatial task (Voyer, et al., 1995). In the mental rotation task, one must imagine how an image would look if it was rotated and either decide whether the imagined rotation matches a given selection. Training on these types of tasks has been shown to improve ability for males and females (Uttal, et al, 2013). Female superiority is shown on verbal tasks such as verbal fluency where participants are asked to name as many items as they can that start with a specific letter. Females also show ad advantage for episodic memory, the memory for events that have occurred (Asperholm, et al., 2019)

More recent reviews by Hyde (2016) and a meta-synthesis by Zell et al. (2015) have reported that gender differences were small to non-existent. They found the largest sex differences were not for cognitive skills, but were largest for motor skills such as throwing. Hyde proposed the Gender Similarity Hypothesis emphasizing the greater similarities than differences between males and females.

Explaining Gender Differences

Several theories have been proposed to explain gender differences in cognition. One approach that has been taken is to emphasize biological factors. Compelling research in this area conducted by Kimura (1999) and Ingalikar et al. (2013). Ingalikar et al. (2013) demonstrated that women’s brains were more highly connected between hemispheres, whereas men showed greater connections within hemispheres. It is important to reflect for a moment on the information from Chapter 5 on neuroplasticity. The brain changes with experience. That differences exist in connectivity in adults does not mean that these differences are preordained. Therefore it is also important to consider experiential theories of gender differences. By this view, gender differences could reflect differences in the socialization of boys and girls by peers, family, teachers, and society. Certain activities can be stereotyped as male or female. Based on stereotypes boys may be reinforced for doing well in math and girls reinforced for writing stories well. Related to the socialization view is that of differential experience. Males and females may be encouraged to take part in different activities and courses. For instance, traditionally boys were more likely to have opportunities to play with blocks, Legos, and other construction toys that encourage spatial development. Changes in gender difference performance have occurred across generations, supporting the idea of social influences on these differences. As we consider explanations of gender differences, it is once again wise to reflect on the Gender Similarities Hypothesis (Hyde, 2007, 2016) that emphasizes there are more similarities between males and females than there are differences. Although we may see some biological differences in the brains of males and females related to behavior, these differences may reflect differences in upbringing and experiences rather than imposing differences in behavior.