The 21st century has brought with it unparalleled levels of diversity in the classroom and the workforce. It is now common to see in elementary school, high school, and university classrooms, not to mention boardrooms and factory floors, a mixture of ethnicities, races, genders, and religious affiliations. But these changes in academic and economic opportunities have not directly translated into an elimination of group disparities in academic performance, career opportunities, and levels of advancement. Standard explanations for these disparities, which are vehemently debated in the...