Expert Perspectives

How Behavioral Science Can Support Long-Term Public Health and Environmental Strategies

Behavioral science and the environmental agenda

Behavioral science refers to a collection of insights into how and why people behave as they do, based on research from the academic fields of economics, psychology, and neuroscience. The observation that humans often act against their own long-term best interests has led behavioral scientists to develop a “dual system” model describing the mental processes that underlie human decision-making. This model argues that most of our day-to-day activities are dictated by our “system 1” or “automatic” mental processing system, which is intuitive, experience-based, and relatively unconscious, while our more conscious, logical, and accurate “system 2” tends to take a back seat. Behavioral scientists argue that the unique interplay of these two systems leads humans to make systematic errors in their decision-making, playing out as behaviors that can seem irrational (Marteau 2017).

The discipline also teaches us not to see these irrationalities simply as mistakes in need of correction. Instead, behavioral science argues that we need to incorporate a better understanding of why and how they occur into the design and implementation of novel behavior-change solutions. Collectively labeled “nudges,” these tend to work by changing the “choice architecture” that surrounds our decision-making, leading to predictable changes in how we respond. Increasingly, nudges are replacing more traditional approaches to behavior change—including education campaigns, financial incentives, and regulations—as a growing body of evidence demonstrates their comparative effectiveness.

The rising popularity of nudges has not escaped the attention of environmental policymakers, who are now realizing that their work stands to be greatly enhanced by integration of theories, methods, and solutions from behavioral science. These solutions could help policymakers influence mass decision-making about what to eat, how to travel, which appliances to use, what to buy, and what to do with waste, all of which have serious implications for the environment when scaled up to the population level (Byerly et al. 2018).

Behavioral science and long-term strategies

For environmental policymakers, behavioral science adds particular value in supporting those tasked with building long-term, low greenhouse gas emission strategies. Key to the success of these strategies is not only the thorough identification and appropriate use of effective solutions to reach strategic goals, but also ensuring that progress is monitored over the course of strategy implementation. Behavioral science can support both elements, providing policymakers with a toolbox of behavior-change approaches to form the building blocks of their strategy, plus a selection of research methods to support monitoring and evaluation (Clayton et al. 2013).

Below, I outline some ideas for environmental policymakers looking to apply behavioral science in their work, drawing on examples from strategies to shift consumers to more sustainable diets. Different foods are known to have different impacts on the environment, with animal-based products, like meat and dairy, associated with a far larger environmental footprint than plant-based alternatives. As a result, encouraging more people to adopt plant-based diets is recognized as one of the most important large-scale behavior changes needed to tackle environmental degradation and ensure a secure food future (Bianchi et al. 2018).

Behavioral science and sustainable diets

One fundamental lesson that environmental policymakers working on sustainable diets have taken from behavioral science is that long-term strategies centered on giving people more information about the environmental footprint of their diets are not, in themselves, enough to bring about change. Knowledge has a small influence on what is eaten (Mullee et al. 2017); food choices are largely automatic and habitual (Marteau 2017).

Recognizing this fact, a range of behavioral science nudges have already been recommended to shift consumers away from animal-based and toward plant-based products, including new and innovative ways to modify the properties (e.g., size, shape, color, design), placement (proximity, frequency, availability), and promotion of food (Bianchi et al. 2018; Kurz 2018; Hyland et al. 2017; Bacon and Krpan 2018). These solutions have attracted much attention from policymakers, in part owing to a preexisting familiarity and support for nudging, an approach already experimented with in policies to tackle the obesity epidemic. Examples include calorie menu labeling (Cook 2016) and limiting exposure to appealing advertising for foods high in sugars, fats, and salt (Economist Intelligence Unit 2017).

Beyond nudging, a second approach to shifting diets that policymakers have used to support long-term strategy building for sustainable diets is to consider the social forces that influence decision-making. Here, the aim is generally to make the target behavior appear the more normal and socially acceptable choice, and is an approach previously used with some success to encourage consumers to shift their food consumption habits. In 2006, for example, the conservation organization Wild Aid worked with the Chinese government to target social norms concerning consumption of shark fin soup—a popular, traditional dish that has been criticized from an ethical and environmental perspective. This campaign used public declarations of opposition to shark fin soup from several high-profile celebrities, followed by a ban on shark products at government functions, thereby signaling to those in positions of authority that they were acting as role models for the public. This example not only proves the benefit of considering the issue of food choice from a social perspective, but also shows how policymakers can work with advocacy groups that have specific expertise in crafting effective behavior-change campaigns (Ranganathan et al. 2016).

The final benefit that behavioral science can offer policymakers is a range of new methods to evaluate the success of the behavior-change approaches that form the basis of their long-term strategies. This comes in the form of field experiments, where data are gathered on the behavior under study—in this case, meat consumption—across groups of individuals who have been exposed to the chosen behavior-change approach, as well as ones who have not. Analysis of this type of data puts policymakers in a far stronger position to state with certainty that their chosen strategy played a causal role in any subsequent behavior changes that were recorded. To date, trials of this kind have been utilized as part of strategy evaluation across a range of different settings, including in schools, workplaces, and through healthcare providers (Mozaffarian et al. 2018), although they have mostly focused on approaches that aim to improve health rather than benefit the environment.

Barriers and facilitators to applying behavioral science to long-term strategy planning

As I noted above, although behavioral science has helped tackle important issues affecting the world’s population, like health, applying his discipline to defense of the environment is relatively new. One factor that has so far appeared to hinder this application is the fact that many potentially effective proenvironmental behavior-change strategies have yet to be tested and proven effective in large, methodologically robust trials. This means that evidence to support their implementation and scaling in the “real world” is lacking. In addition, where knowledge on this topic is available, it has tended to remain siloed within academic or other specialist organizations or be presented in such complex ways that it is too difficult to interpret and apply in practice (Reynolds 2010).

What is now needed is not only more applied research at the intersection of behavioral science and environment, but also translation and communication of the results to policymakers, alongside easy-to-use guidance on how to implement similar solutions in their countries. The key aim here is to increase access to information that can allow policymakers to consider behavioral science early in the policy development process, leading to solutions that are fully behaviorally informed and can be subjected to robust experimental evaluations. A number of good resources already are available on this topic, including the Organization for Economic Co-operation and Development’s Behavioural Insights and Public Policy: Lessons from around the World (OECD 2017), which I recommend policymakers working across a range of fields look to for guidance.

In terms of behavioral science’s application to the promotion of sustainable diets in particular, it is worth noting that the food industry has proved a valuable source of innovative new solutions to encourage uptake of plant-based options. Indeed, industry has responded far more rapidly than policymakers to growing consumer demand for more environmentally friendly, yet tasty, options by creating new products and dishes, increasing their distribution, and strategically marketing their benefits. All these actions have increased the visibility of plant-based diets as the more sustainable option, thereby supporting the work of policymakers.

Policymakers in other areas could also make real gains by working with industry actors where possible. Cross-learning and collaboration between industry and government can ensure that changes implemented by each sector are acceptable to the other, leading to the development of solutions that have greater impact in shifting consumers’ choices, but without substantially harming a company’s bottom line or leading to industry disengagement with the broader environmental agenda.

For policymakers working on long-term proenvironmental strategies, behavioral science can offer tools and methods to support effective strategy building and proof that their approaches are better than available alternatives. Working alongside industry experts, consultants, and academics who possess behavioral science expertise would facilitate this process, as would more effective translation of key concepts from the discipline to those who are in a position to effect change.


Bacon, L., and D. Krpan. 2018. “(Not) Eating for the Environment: The Impact of Restaurant Menu Design on Vegetarian Food Choice.” Appetite 125: 190–200. doi:10.1016/J.APPET.2018.02.006.

Bianchi, F., E. Garnett, C. Dorsel, P. Aveyard, and S.A. Jebb. 2018. “Restructuring Physical Micro-environments to Reduce the Demand for Meat: A Systematic Review and Qualitative Comparative Analysis.” Lancet Planetary Health 2(9): e384–97. doi:10.1016/S2542-5196(18)30188-8.

Byerly, H., A. Balmford, P.J. Ferraro, et al. 2018. “Nudging Pro-environmental Behavior: Evidence and Opportunities.” Frontiers in Ecology and the Environment 16 (3): 159–68. doi:10.1002/fee.1777.

Clayton, S., C. Litchfield, and E.S. Geller. 2013. “Psychological Science, Conservation, and Environmental Sustainability.” Frontiers in Ecology and the Environment 11 (7): 377–82. doi:10.1890/120351.

Cook, E. 2016. “Calorie Labeling on Restaurant Menus and Vending Machines.” United States Environmental Protection Agency (July): 1–4.

Economist Intelligence Unit. 2017. “The Impacts of Banning Advertising Directed at Children in Brazil.” August.

Hyland, J.J., M. Henchion, M. McCarthy, and S.N. McCarthy. 2017. “The Role of Meat in Strategies to Achieve a Sustainable Diet Lower in Greenhouse Gas Emissions: A Review.” Meat Science 132: 189–95. doi:

Kurz, V. 2018. “Nudging to Reduce Meat Consumption: Immediate and Persistent Effects of an Intervention at a University Restaurant.” Journal of Environmental Economics and Management 90: 317–41. doi:

Marteau, T.M. 2017. “Towards Environmentally Sustainable Human Behaviour: Targeting Non-conscious and Conscious Processes for Effective and Acceptable Policies.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 375 (2095).

Mozaffarian, D., S.Y. Angell, T. Lang, and J.A. Rivera. 2018. “Role of Government Policy in Nutrition: Barriers to and Opportunities for Healthier Eating.” British Medical Journal 361: k2426. doi:10.1136/bmj.k2426.

Mullee, A., L. Vermeire, B. Vanaelst, et al. 2017. “Vegetarianism and Meat Consumption: A Comparison of Attitudes and Beliefs between Vegetarian, Semi-vegetarian, and Omnivorous Subjects in Belgium.” Appetite 114: 299–305. doi:10.1016/j.appet.2017.03.052.

OECD (Organisation for Economic Co-operation and Development). 2017. Tackling Environmental Problems with the Help of Behavioural Insights. doi:10.1787/9789264273887-en.

Ranganathan, J., D. Vennard, R. Waite, et al. 2016. Installment 11 of Creating a Sustainable Food Future: Shifting Diets for a Sustainable Food Future. April. Washington, DC: World Resources Institute.

Reynolds, L. 2010. “The Sum of the Parts: Can We Really Reduce Carbon Emissions through Individual Behaviour Change?” Perspectives in Public Health 130 (1): 41–46. doi:10.1177/1757913909354150.

All the interpretations and findings set forth in this expert perspective are those of the author alone.