It's sad that in this day and age, such a seemingly archaic bias would still be around in our school systems. But Sue Wilson, author of “Gender bias by teachers in math class affects girls later,” suggests that math teachers favor boys over girl students. According to research cited in the article, teachers have a tendency to grade their male students more favorably than females, as they hold the latter to higher level. Consequently, female students may receive lower grades due to a false assumption that they need rigorous grading scales. Earning lower grades, biased treatment, and unrealistic expectations then lead female students to have lower self-esteem than their male counterparts.