This undergraduate textbook reviews psychological research in the major areas of reasoning and thinking: deduction, induction, hypothesis testing, probability judgement, and decision making. It also covers the major theoretical debates in each area, and devotes a chapter to one of the liveliest issues in the field: the question of human rationality. Central themes that recur throughout the book include not only rationality, but also the relation between normative theories such as logic, probability theory, and decision theory, and human performance, both in experiments and in the world...