Applied Behaviour Analysis (ABA) is a specific psychological treatment dating back to early 20th century. It is best known for its success in treating individuals with Autism Spectrum Disorder (ASD) and other developmental disabilities (e.g., Down Syndrome, Intellectual Disabilities).Decades of research have shown that intensive ABA treatment is the most successful approach for children with Autism, and it is widely recognised by a number of sources including the U.S. Surgeon General, the American Academy of Paediatrics, and the National Institute of Mental Health, Irish Psychological Society etc. 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