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 scientific community and popular press, range from the view that women and minorities are genetically endowed with inferior abilities to the view that members of these demographic groups are products of environments that frustrate the development of the skills needed for success. Although these explanations differ along a continuum of nature vs. nurture, they share in common a presumption that a large chunk of our population lacks the potential to achieve academic and career success. In contrast to intractable factors like biology or upbringing, the research summarized in this book suggests that factors in ones immediate situation play a critical yet underappreciated role in temporarily suppressing the intellectual performance of women and minorities, creating an illusion of group differences in ability. Research conducted over the course of the last fifteen years suggests the mere existence of cultural stereotypes that assert the intellectual inferiority of these groups creates a threatening intellectual environment for stigmatized individuals - a climate where anything they say or do is interpreted through the lens of low expectations. This stereotype threat can ultimately interfere with intellectual functioning and academic engagement, setting the stage for later differences in educational attainment, career choice, and job advancement.