There are many different theories—in many different disciplines—that attempt to explain or account for human language and cognition. With so many different theories available, what is unique or special about Relational Frame Theory? We believe the functional, contextualistic approach of RFT to understanding complex human behavior has led to a system of analysis that offers many advantages over the traditional structural and “information transmission” models of language and cognition (Blackledge, 2003). Among these advantages are that it is parsimonious, and focuses on analyzing behavior in a way that allows for precision, scope, and depth.