Behavior Analysis is the science of behavior. Its underlying philosophy is behaviorism, which is based upon the premise that attempting 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, rather than less tangible concepts such as the mind and willpower. To date, basic behavior-analytic scientists have conducted thousands of studies to identify the laws of behavior; that is, 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. Applied behavior analysts have been using this information to develop numerous techniques and treatment approaches for analyzing and changing behavior, and ultimately, to improve lives. Because this approach is largely based on behavior and its consequences, the techniques generally involve teaching individuals more effective ways of behaving and making changes to social consequences of existing behavior.

Applied Behavior Analysis (ABA) has been empirically shown to be effective in a wide variety of areas, including parent training, substance abuse treatment, dementia management, brain injury rehabilitation, occupational safety intervention, among others. However, because ABA was first applied to the treatment of individuals with intellectual disabilities and autism, this practice area has the largest evidence base and has received the most recognition.