Recent research shows that anxiety not only fails to produce good decisions but seems “exquisitely designed” to produce bad ones. In local and global health, where anxiety often thwarts good decision making, efforts to improve how choices are made have focused on collaboration and the use of scientific evidence. These efforts may have some relevance to an anxious public deciding this week whether the United Kingdom remains in the European Union.

Patient centered care envisions collaboration and shared decision making. One recommended way to improve medical decision making is through the application of prospect theory. This theory is rooted in economics and psychology, and addresses the behavioral underpinnings of choice in the face of uncertainty.

It recognizes, for example, that patients with poor prospects are more likely to take risks and make irrational choices by disregarding low probabilities. While this may mean that they are more willing to undergo treatment with less probability of success, it may also explain their embrace of dubious or pseudoscientific interventions to recoup their losses. The goal of prospect theory as applied to healthcare is to augment Choosing Wisely guidelines by addressing the patient’s tendency of thinking in relative rather than absolute terms and the natural tendency of some patients to engage in risk averse or risk seeking behavior.

In global health, achieving stated goals has been thwarted by unwise policy choices by anxious decision makers—fearful perhaps of upcoming elections, appearing weak to the public, or failing to satisfy powerful vested interests. These choices typically share three features: they tend to be dismissive of (scientific) evidence, dismissive of the opinion of peers, and dismissive of victim impact.

Among the more striking examples is the former President of South Africa Thabo Mbeki’s questioning of the link between HIV and AIDS; he also told the Washington Post: “Personally, I don’t know anybody who has died of AIDS.” The South African government’s failure to provide an antiretroviral treatment program from 2000-05 has, in fact, been estimated to have contributed to at least 330 000 deaths in the country.

Similarly, Canadian Prime Minister Stephen Harper’s support of asbestos mining and export dumbfounded his peers when he promised “this government will not put Canadian [asbestos] industry in a position where it is discriminated against in a market where it is permitted.” Recent assertions by Donald Trump, potential future leader of the US, that global warming is a hoax even as CO2 levels reach new milestones this past week are a reminder of this irrationality.

Policy outliers are becoming less acceptable. Indeed, 750 experts contributing to the Global Risk Report 2016 confirm that catastrophic events (such as profound large scale involuntary migration, epidemics, close to home terrorism, and “natural disasters”) are becoming more commonplace, more impactful, more immanent, more reflective of real time experience, and more anxiety producing. These experts insist that only collaborative action based on scientific evidence will yield an effective and efficient response. Most industrial countries have developed global health strategies; developments in global health diplomacy, global health security, and international relations reflect this trend.

Set against this background, the desire to leave the European Union seems to be, conceptually and practically, a move in the opposite direction. While countries from South America to the Far East are widening and deepening European style regional unions, Brexit would suggest a negation of the benefits of aggregation.

Prospect theory tells us that those who feel they have not participated in the benefits of EU membership or have lost benefits may want to take the risk of exiting—feeling, perhaps, that they have nothing to lose and perhaps something to gain or regain. Prospect theory tells us that we don’t need to cite xenophobia, anti-immigrationism, or racism to explain this support for Brexit; it may result from ordinary people acting in ways anticipated by behavioral economics.

The decision of whether the United Kingdom ought to stay in the European Union casts many shadows—some long, some dark—yet the most regrettable shadow is how fear-mongering by both camps has diminished the process.

Chris Simms is a professor at Dalhousie University, School of Health Administration, Halifax, Canada; he spent many years living and working in Africa’s health sector.

Competing interests: CS has participated in research that was funded by the EU.