Celebrating variability and a call to limit systematisation: the example of the Behaviour Change Technique Taxonomy and the Behaviour Change Wheel.

Within any discipline there is always a degree of variability. For medicine it takes the form of Health Professional's behaviour, for education it's the style and content of the classroom, and for health psychology, it can be found in patient's behaviour, the theories used and clinical practice. Over recent years, attempts have been made to reduce this variability through the use of the Behaviour Change Technique Taxonomy, the COM-B and the Behaviour Change Wheel. This paper argues that although the call for better descriptions of what is done is useful for clarity and replication, this systematisation may be neither feasible nor desirable. In particular, it is suggested that the gaps inherent in the translational process from coding a protocol to behaviour will limit the effectiveness of reducing patient variability, that theory variability is necessary for the health and well-being of a discipline and that practice variability is central to the professional status of our practitioners. It is therefore argued that we should celebrate rather than remove this variability in order for our discipline to thrive and for us to remain as professionals rather than as technicians.