Nudge theory in public health – a way to achieve behavioural change?

Behaviour change prompted by nudge theory alone is not going to solve complex public health problems such as obesity and chronic disease, according to UK public health leader Professor Mike Kelly.

Professor Kelly, a former Director of the Centre for Public Health at the National Institute for Health and Care Excellence (NICE), spoke at a recent public forum jointly hosted by The Australian Prevention Partnership Centre and the Hospital Alliance for Research Collaboration.

The focus of his talk was the British experience in using nudge theory for public health interventions. Nudge theory became popular after the publication of an economics text, Nudge: Improving Decisions About Health, Wealth, and Happiness, by Richard H Thaler and Cass R Sunstein.

Professor Kelly,  who is an Honorary Senior Visiting Fellow at the University of Cambridge’s of Public Health, said nudge theory was based on the idea that about 80% of human behaviour is automatic, with people responding to cues in the environment, sometimes known as choice architecture.  An example was placing a fruit bowl on the front counter in a school canteen to encourage children to buy more fruit. An unhealthy nudge might be placing sweets near supermarket checkouts to encourage children to pester their parents to purchase.

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Nudge theory and public health interventions

Professor Kelly said public health interventions traditionally focused on the other 20% of behaviour change, the more deliberate type of decision making in which we are expected to take in public health messages, interpret and process them and then change our behaviour, such as stopping smoking or exercising more.

While nudge could apply to microenvironments, such as the school canteen, it also had a macro application in terms of system changes to prevent chronic disease, which is the focus of The Australian Prevention Partnership Centre.

“If you are going to think about nudging in a broader, scaled-up way, you have to think systems-wide change, with the focus on the nature of the built environment, on architecture, planning, transport systems, food systems and so on.”

Professor Kelly said the jury was still out on whether nudge theory could work in public health. “We need more research, especially in terms of physical activity.”

He sees nudge as just one part of the armoury needed to tackle obesity and chronic disease.

“If we’re looking to change obesity and improve rates of physical activity, we need that multi-pronged, multi-layered approach that involves everybody, from governments to individuals,” he said. “All have a role to play, some of which will be about nudges and automatic responses to things in the environment, but some of which will still rely on state regulation.”

Behavioural complexity

He said behaviour and changing behaviour are complex.

“Humans do things that make their lives easier, including taking short cuts in their thinking and actions and if you can harness those towards healthy ends, all well and good. But that is not the be all and end all of behaviour change.

“Tobacco and the reduction in levels of smoking in Australia, Great Britain, the US and Canada have been a consequence of multi-layered and multi-level strategies, including nudge, that have been integrated with each other. This has taken decades and it may take just as long with obesity and chronic disease.”

Nudge and ethics

Professor Kelly said the ethics of nudge theory had been questioned by some in public health who claimed it manipulated people to healthy choices without them knowing it.

“The counter argument is that people are being nudged to buy sugary drinks and fattening food in an obesogenic environment that nudges them to eat at every opportunity and no one’s consent has been sought for that, so that’s just as unethical.”

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