What is the purpose of a taxonomic system for prevention? From a functional contextualist’s perspective (Biglan and Hayes 1996; Hayes et al. 2012), one would hope that the system contributes to the prediction and influence of behavior with precision, scope, and depth (Biglan and Hayes 1996; Hayes et al. 2012). We precisely predict and influence a phenomenon when we can use a limited number of concepts that unambiguously apply to the phenomenon or its context. Our analyses are broad in scope when they apply to a wide range of phenomena. An analysis has depth when it coheres with analyses at other levels, such as an analysis of the environmental influences on behavior that is consistent with an analysis of the biological processes that mediate these influences on behavior. In this sense, to say that a taxonomic system is functional implies that it contributes to prediction and influence.

The Precision of the Proposed Taxonomy

Dr. Foxcroft argues that the current system, which characterizes prevention as universal, selective, and indicated, should be supplemented by distinguishing preventive interventions in terms of whether they are environmental, developmental, or informational. He argues that the latter categories get at the function or purpose of the intervention. Environmental interventions are those “intended to reduce the availability of opportunities to engage in risky health behaviours in a particular setting.” Developmental interventions “are intended to shape the socialisation and development of young people as they grow and mature so that they are less susceptible to any such opportunities for risky behaviour that are present in the environment.” Informational interventions “are intended to directly improve knowledge and awareness, for example through challenging pre-existing beliefs and attitudes about health risk behaviours, or by simply providing information about risks and harms.” Apparently, these categories are “functional” in the sense that they describe three types of functional effects on the behavior to be prevented.

One concern I have with this taxonomy concerns the precision of its concepts. One would hope that each concept denotes a set of events that is distinct from the events denoted by the other concepts. However, I see considerable ambiguity and overlapping in the meaning of these terms.

Almost any intervention could be considered environmental in the sense that the only possible way to influence the behavior of individuals is through their environment. Information delivered to the person exists in the environment. All the events affecting a person’s development are also in the environment. Moreover, so-called environmental interventions surely provide information to the person and change norms for a behavior. Also, wouldn’t many of the interventions that affect a young person’s development provide information? For these reasons, I am doubtful that interventions can be reliably coded into these categories. At a minimum, reliable coding would need to be demonstrated before the system could be used.

A Framework that May Have Greater Utility

My larger concern, however, has to do with whether the system itself would be functional in the sense that it contributes to improving the efficacy of prevention science and practice. From the standpoint of organizing our thinking about prevention in terms that will move us toward increasingly effective and population-wide prevention, it seems useful to focus on the features of the environment that confer the most significant risk or protections affecting important outcomes. Thus, rather than focusing on features of the intervention, it may be more useful to focus on the functional features of environments that affect well-being.

Elsewhere, colleagues and I have argued that we can characterize environments that prevent diverse psychological, behavioral, and health problems and nurture prosociality in terms of four facets (Biglan et al. 2012). First, they minimize biologically and socially toxic conditions. Second, they teach, promote, and richly reinforce prosocial behavior and values. Third, they limit influences and opportunities that promote problem behavior. And fourth, they promote psychological flexibility, which involves the pragmatic and resilient pursuit of one’s values even in the face of significant psychological and environmental obstacles (e.g., Biglan et al. 2008). In our analysis of the key features of preventive interventions, we concluded that one or more of these features characterize effective preventive interventions.

If we are going to maximize the impact of prevention science, I think we need the same kind of effort that characterized the tobacco control movement. Just as the American culture of smoking was dramatically changed by a well-organized and science-driven movement to reduce smoking, we need a broad and ambitious effort to organize society to increase the prevalence of nurturing families, schools, and all other environments that can be shown to affect human wellbeing.

From the standpoint of a pragmatic or contextualist view of science, our taxonomic or conceptual systems are less a matter of describing the features of the world than they are verbal devices that guide us to more effective action (Long 2013). If Dr. Foxcroft’s system proves to be reliably codable, it will indicate that he has precisely discerned features of the prevention landscape. However, the question will remain whether the system will foster more effective prevention research and practice.

I believe that the most important features of the prevention landscape we must draw attention to have to do with the functional features of environments that either perturb or enhance development. I would argue that the four dimensions with which we have characterized nurturing environments pinpoint the most important things that public health policy, and further research should address if we are to significantly reduce the burden of society’s psychological, behavioral, and health problems.