In every area of life science if you stop and ask the question about a structure or process “why is this like that” the answer will ultimately be “because it evolved that way.” If the answer is thoughtful, the details of how it evolved will then be presented. In every area of the life sciences it is like that. Well, except one. Behavioral science.


The contextual behavioral science tradition views itself as part of evolution science. The foundation of CBS can be found in Skinner’s approach, and he made that argument very explicitly. The earliest CBS writings amplified that argument.

I think we can summarize the essence of how to use evolutionary thinking deliberately into this simple statement: foster variation fitted to context, that can be selected and retained, at the right dimension and level. In future newsletters I will show how powerful these six concepts of variation, selection, retention, context, dimension, and level can clinically, but in a new article my students and I show how powerful they can be in arriving at a new approach to language and cognition.

This new article (Hayes, Sanford, & Chin, 2017) briefly describes the history of evolutionary thought in behavioral psychology and CBS, and applied the “six concept” system to the research program in Relational Frame Theory, looking both back over the studies done, and forward over the studies that need to be done.

It is published in the Journal of Contextual Behavioral Science and the publisher has made the article available for free for a limited time (until the end of October) if you use this link:

Hayes, S. C., Sanford, B. T., & Chin, F. (2017). Carrying the baton: Evolution science and a contextual behavioral analysis of language and cognition. Journal of Contextual Behavioral Science, 6, 314-328. doi:10.1016/j.jcbs.2017.01.002