Deficit thinking refers to the notion that students (particularly low income, minority students) fail in school because such students and their families experience deficiencies that obstruct the learning process (e.g. limited intelligence, lack of motivation and inadequate home socialization). The authors of this text argue that deficit thinking is a pseudo-science founded on racial and class bias. They trace the evolution of deficit thinking from the American colonial period to the present, critiquing the model and offering more plausible explanations of why students fail.