Behavioral decision theory (BDT) is an interdisciplinary field that draws on insights from psychology and econom­ics to provide a descriptively realistic picture of human decision making. BDT shares with economics the idea that human behavior can be understood as a purposeful attempt to achieve well-being, or "utility." It shares with psychol­ogy the recognition that people have limited information-processing capacity as well as limited opportunities to acquire some of the specific skills needed for effective decision making. The combination of these perspectives leads BDT to focus on ways that real-world decision making deviates from the stylized assumptions of economics — and on ways in which performance might be improved.

Behavioral decision theory can be divided into two subtopics: judgment and choice. Judgment refers to information-processing tasks, assessing properties of situations such as the probability of events or patterns of causality. Violations of normative models of judgment are referred to as "biases." Choice deals with how people use information gleaned from judgment, and from reflection on their own needs and desires to select a course of action. Behavioral violations of normative models of choice are labeled "anomalies."