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Rethinking public health using behavioural science


August 23, 2017 Michael Hallsworth and Michael Sanders

How could – and should – findings from behavioural science make us approach public health differently?

This week, BIT offered a provocative answer to this question in the journal Nature Human Behaviour.

It was also a question addressed by over 100 academics and practitioners at a recent workshop organised by BIT and Harvard’s Behavioral Insights Group.

The workshop tackled five challenges in public health – diet, physical activity, preventative screening, antimicrobial resistance, and vaccinations – with an academic and a practitioner from each area paired for each topic.

For example, we heard from Peter Ubel from Duke University about the current state of research on how our eating is influenced by labelling, availability of choices, and cultural attitudes to food.

“The Big Mac is 30% larger than le Big Mac in France, but Americans eat the Big Mac in half the time the French take to eat le Big Mac”
Peter Ubel, Duke University

He was followed by Sarah Bleich, a former White House Policy Fellow (now at Harvard’s School of Public Health), who showed how the US government has put these findings into practice through its food guidance.

But perhaps the most direct challenges to public health thinking came from the two opening talks.

On the first day, Harvard University’s Ichiro Kawachi gave an overview of the research that shows that behaviour is much more automatic and habitual than is assumed by the models underpinning public health. As a result, many policies may be missing the mark.

On day two, BIT’s Director of Health Michael Hallsworth pushed this thinking further towards its practical implications. He argued that public health should do two things differently.

First, focus on approaches that require very little or no effort, particularly substitution, rather than trying to ensure people make a conscious and effortful conversion to a healthy lifestyle.

Second, to be more willing to help people shift to marginally healthier options, even if they aren’t the healthiest available.

These changes can be surprisingly controversial. For example, electronic cigarettes offer a clear case where easy substitution could reach people who can’t quit tobacco in other ways. But the very thing that makes them an easy and appealing alternative – their similarity to tobacco cigarettes – has triggered opposition from some in the public health community, opposition that is not justified by the evidence, as Public Health England itself notes.

Moreover, we tend to undervalue the cumulative impact of repeated marginal changes. Take obesity. The energy imbalance that leads to obesity is relatively small, around 100 calories, but repeated over time. A repeated marginal shift could be enough to close this gap.

More importantly, these marginal moves could lead to wider changes in the food system. They may create new incentives for food producers and retailers to develop, stock and promote healthier versions of similar foods, effectively competing for these marginal choices. In the end, even those who did not shift their behaviour would get health benefits from the ensuing food reformulation.

You can read more about these ideas in our new article in Nature Human Behaviour, out this week.

The Harvard-BIT workshop was funded from a grant from the Alfred P Sloan Foundation to increase collaboration between academics and policymakers in the use of behavioural science. We think that collaborations like this are essential to improve public health, and we will continue to work with public sector partners at a local, national and international level to make them happen.

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