24 January 2019

Smoking areas and recycling are two examples where people’s behaviour is pushed in a particular direction. It’s called “nudging”. A doctoral thesis at Linköping University investigates why we accept being ushered, or nudged, towards a certain outcome – or why we don’t.

Elephant nudgingElephant being pushed in the right direction. Photo credit NightOwlZASmoking areas and recycling are two examples where people’s behaviour is pushed in a particular direction. It’s called “nudging”. A doctoral thesis at Linköping University investigates why we accept being ushered, or nudged, towards a certain outcome – or why we don’t. Nudging is a push in the right direction. It makes it easier for us to do the right thing. In more complex terms, a nudge is when someone, such as a decision-maker, uses an understanding of psychological mechanisms to influence our behaviour, in order to get us to do what we want. Quitting smoking, for example. In this context, nudging makes it difficult for us to continue smoking, for instance by making us go to a smoking area.

Amongst Swedish decision-makers, nudging has increased in the hope that it can encourage people to make good decisions, for instance regarding the environment. In his doctoral thesis, William Hagman has investigated what it is that makes us accept – or not accept – an intervention by the state. William Hagman. Photo: Thor Balkhed

“If decision-makers are to use nudges effectively they have to understand how to devise them, and why people find them acceptable or not. Nudges that haven’t worked have resulted in strong backlashes”, says William Hagman from the Division of Psychology, and member of JEDI, the lab for behavioural and neuroeconomic research at Linköping University.

One example of a nudge from the state that didn’t work was when Chile changed the rules regarding organ donation. Instead of people consenting to donation, the new default situation was that everybody’s organs went to donation when they died – provided they didn’t actively decline. But instead of more organ donations they ended up with fewer. People felt that the state was trying to “take” their organs, and the number of people who de-registered exceeded the number of people who had registered in the old system.

“If people perceive the nudge as manipulation, it has failed. A nudge mustn’t be misleading. The contribution of my thesis is a model that can function as a checklist when devising a nudge. What makes it work, and whether it will be accepted”, says William Hagman.
Who benefits, and what is the aim?

William Hagman’s doctoral thesis shows that our acceptance of a nudge is affected by what its aim is. For instance, if we sympathise with the idea of a better environment, we accept recycling. But, acceptance is affected by who it is that benefits from the nudge. If we ourselves gain from it, we’re more prone to accept it than if society benefits. And nudges that deliver individual benefits are viewed as being less detrimental to our freedom of choice.

Another finding is that our attitudes to the source of the nudge are important in how we assess it. We’re more likely to accept a nudge if it comes from a political party we like. For instance Green Party sympathisers are more favourable towards carbon offsetting if it is proposed by the Green Party, than if, say, the Sweden Democrats propose it.

William Hagmans checklist for designing a nudge:

A few pointers on nudge technique:

  • Conscious or unconscious?
    Is the nudge intended to influence an intuitive behaviour, or to get the person to reflect on his or her behaviour? An intuitive nudge requires fewer mental resources, but sometimes it’s necessary to make people consider something more actively.

  • Technique that prevents or encourages mental deviations?
    To help people achieve their goals, do you want to prevent or encourage the mental deviations they tend to make?

  • Transparent or not?
    Non-transparent nudges can tend to be perceived as manipulation.

  • The social aspect
    A nudge can make use of norms or group affiliations to highlight or influence a behaviour. For instance, pointing to a norm in order to show that a behaviour is more common than most people believe. E.g.: “70% of those in your age group save for their retirement”, to show that someone is outside the norm.

  • It should be easy to use
    Otherwise people are less likely to act on the nudge.

Tips to ensure nudge acceptance:

  • The aim
    Acceptance of a nudge is determined by its aim.
  • How the nudge is designed (see points above)

  • Who will benefit
    Acceptance is more probable if the individual benefits from the nudge, than if society benefits.

  • Detrimental to freedom of choice?
    Nudges that are seen to adversely affect freedom of choice are less accepted. Nudges that deliver individual benefits are seen as less detrimental to our freedom of choice.

  • The nudge recipient
    Get to know the recipient of the nudge. For instance, trying to make use of social norms without understanding what is important to the target group can result in the nudge having unintended results.


    The doctoral thesis:
    When are nudges acceptable?: Influences of beneficiaries, techniques, alternatives and choice architects, William Hagman (2018), Linköping University, Department of Behavioural Sciences and Learning, Psychology. Faculty of Arts and Sciences. DOI: 10.3384/diss.diva-152788

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