The scores of the GAT show that girls perform better than the boys in the Written Communication section of the GAT while boys perform better in the Mathematics section. In fact, the difference between the two results is equal: girls perform better in Communication to the same extent as boys perform better in Mathematics. Interestingly, this appears to confirm traditional perceived gender differences between the genders. So are boys simply naturally skilled in mathematics? A recent article in American Psychologist by Janette Hyde examined this hypothesis in depth (along with other differences between the genders) and found that this wasn't necessarily so; instead these type of test results could be explained by self-fulfilling prophecy.
'In one experiment, male and female college students with equivalent math backgrounds were tested (Spencer et al., 1999). In one condition, participants were told that the math test had shown gender difference in the past, and in the other condition, they were told that the test had been shown to be gender fair—that men and women had performed equally on it. In the condition in which participants had been told that the math test was gender fair, there were no gender differences in performance on the test. In the condition in which participants expected gender differences, women under performed compared with men. This simple manipulation of context was capable of creating or erasing gender differences in math performance.' (Hyde, 2005, p589).
Therefore, in a social context where girls expect to perform worse than boys in the mathematics section of the GAT, perhaps they actually do; equivalently, because the boys expect to perform worse in communication (which is seen as a feminine trait) they doom themselves to a similar result. This is an interesting theory that is worth further investigation especially as how it may relate to the examination and coursework performance by students.