"One year with a male English teacher would eliminate nearly a third of the gender gap in reading performance among 13 year olds and would do so by improving the performance of boys and simultaneously harming that of girls. Similarly, a year with a female teacher would close the gender gap in science achievement among 13 year olds by half and eliminate entirely the smaller achievement gap in mathematics."
In kindergarten, boys and girls do equally as well on tests of reading, general knowledge, and mathematics. By third grade, boys have slightly higher mathematics scores and slightly lower reading scores. As children grow older, these gaps widen. Between 9 and 13 years of age, the gender gaps approximately double in science and reading. Between 13 and 17, the gap in science continues to expand but there is little growth in the math or reading gap. The size of the gaps is not trivial. The underperformance of 17-year-old boys in reading is equivalent to 1.5 years of schooling, and though men continue to be over-represented in college level science and engineering, girls are now more likely to go to college and persist in earning a degree.
The source of these gender differences has long been a topic of heated debate. Though tests of general intelligence suggest no overall differences between men and women, there are large gender differences in scores on specific cognitive tasks. Men perform better at certain spatial visual tasks; women excel verbally. While these differences may someday be traced back to known differences in hormonal exposure and male and female brain structures, it is also possible that differences in academic development arise from the fact that male and female teachers have a tendency to treat boys and girls differently in the classroom.
In Teachers and the Gender Gaps in Student Achievement (NBER Working Paper No. 11660), author Thomas Dee uses data from the nationally representative National Education Longitudinal Study of 1988 to examine the consequences of gender interactions within classrooms. The outcome measures include test scores, teacher perceptions of student performance, and measures of students' intellectual engagement (for example, whether a student was afraid to ask questions in a particular class, looked forward to the class, and saw the class as useful for the future).
Dee finds that gender interactions between teachers and students have significant effects on these important educational outcomes. Assignment to a teacher of the opposite sex lowers student achievement by about 0.04 standard deviations. Other results imply that just "one year with a male English teacher would eliminate nearly a third of the gender gap in reading performance among 13 year olds and would do so by improving the performance of boys and simultaneously harming that of girls. Similarly, a year with a female teacher would close the gender gap in science achievement among 13 year olds by half and eliminate entirely the smaller achievement gap in mathematics."
Female science teachers appeared to reduce the probability that a girl would be seen as inattentive in science, though this had no discernable effect on girls' science achievement. However, female history teachers significantly raised girls' history achievement. And, boys were more likely to report that they did not look forward to a particular academic subject when it was taught by a female.
Overall, the data suggest that, "a large fraction of boys' dramatic underperformance in reading reflects the classroom dynamics associated with the fact that their reading teachers are overwhelmingly female." According to the U.S. Department of Education's 1999-2000 Schools and Staffing Survey, 91 percent of the nation's sixth grade reading teachers, and 83 percent of eighth grade reading teachers are female. This depresses boys' achievement. The fact that most middle school teachers of math, science, and history are also female may raise girls' achievement. In short, the current gender imbalance in middle school staffing may be reducing the gender gap in science by helping girls but exacerbating the gender gap in reading by handicapping boys
-- Linda Gorman