ABA is the science of behavior, with a history extending back to the early 20th century. Its guiding philosophy is behaviorism, which is based on the premise that attempts to improve the human condition through behavior change (e.g., education, behavioral health treatment) will be most effective if behavior itself is the primary focus.

To date, behavior-analytic scientists have conducted thousands of studies to identify the laws of behavior—the predictable ways in which behavior is learned and how it changes over time. The underlying theme of much of this work has been that behavior is a product of its circumstances, particularly the events that immediately follow the behavior. Behavior analysts have used this information to develop numerous techniques and treatment approaches for analyzing and changing behavior, and ultimately, to improve lives. Because this approach applied behavior analysis (ABA) is largely based on behavior and its consequences, techniques generally involve teaching individuals more effective ways of behaving through positive reinforcement and working to change the social consequences of existing behavior. Treatment approaches based on ABA have been empirically shown to be effective in a wide variety of areas (see ABA Subspecialty Resources).