[Sociocultural] explanations are vulnerable to a number of criticisms. To begin with, it is unclear to what extent current social influences actually point in the direction these explanations presuppose. According to one study, by four years of age, girls tend to assume that boys are academically inferior, and by seven, boys assume the same thing. Similarly, teachers tend to view their female students as superior at maths and reading, even when aptitude tests indicate that the boys are doing better. Popular culture often mirrors these trends, with girls depicted as academically superior to boys (consider, for instance, Bart and Lisa from The Simpsons, and Ron and Hermione from the Harry Potter series.