Pragmatic nihilism: how a Theory of Nothing can help health psychology progress.

Health psychology developed a plethora of theories to explain and change a wide variety of behaviours. Several attempts have been undertaken to build integrative theories, some even striving for a Theory of Everything. We argue against these efforts, arguing that instead a 'pragmatic nihilism' perspective may be more fruitful to understand and change health behaviours. The first tenet of pragmatic nihilism is that psychological variables are usefully considered as metaphors rather than referring to entities that exist in the mind. As a consequence, the second tenet emphasizes theories' definitions and guidelines for the operationalisation of those variables. The third tenet of pragmatic nihilism is that each operationalisation represents an intersection of a variety of dimensions, such as behavioural specificity and duration, and most importantly, psychological aggregation level. Any operationalisation thus represents a number of choices regarding these dimensions. Pragmatic nihilism has two implications. First, it provides a foundation that enables integrating theories in a more flexible and accurate manner than made possible by integrative theories. Second, it emphasizes the importance of operationalisations, underlining the importance of investing in the careful development of measurement instruments, thorough reporting of measurement instruments' specifics and performance, and full disclosure of the instruments themselves.