Is nudging enough to achieve behavioral changes at short notice?

Nudging is a powerful tool in helping people make the right decisions without forcing them to do so. It has been widely used by public authorities to help the general public adopt behaviors beneficial to them, that otherwise they would tend not to adopt. In his groundbreaking book “Nudge”, Nobel prize winner Richard Thaler gives the example of pension schemes in the USA: simply changing from on “opt-in” for savings to an “opt-out” led to dramatic increases in prudent savings habits for American employees.1

But in the case of epidemiological emergency, is this enough? And how can individual healthcare providers use these techniques?

Nudging consists of taking our irrational biases into account in order to create policy and communications that naturally entice people to change their behavior.  Thaler and others developed several tools that are highly effective in this.1 One that can be particularly useful both for authorities and for individual healthcare providers is loss aversion. 

Loss aversion

If you ask someone to buy tickets to a concert by a musician they don’t really like, they’re not likely to spend much on the ticket, if anything.  If, though, you give them the tickets and then someone offers to buy them, they’re likely to want more for them than they would have been willing to spend in the first place.  This was one of Daniel Kahneman’s most surprising findings and it demonstrates what is known as loss aversion.  When we need to give up something we possess, this causes us to value it more2.

How can these techniques be used to nudge people with respect to health-related behavior, such as “social distancing”?  Let’s consider two approaches when dealing with a patient:

“Close contact is a vector for the virus.  You should avoid leaving your home, and if you do come into contact with others you should maintain a distance of at least one meter until further notice.  This is good for you and for everyone else3.”

All the facts are there, but will it work?  How about the following:

“My other patients have been joining in the effort to fight this virus by remaining at home and maintaining a distance of at least one meter with others. I’m sure I can count on you to do the same and help accelerate an end to this crisis. Every day we do that is another little victory.”

Here we’ve established a social norm (everyone is doing this), framed the effort as a fixed project to end the crisis, set a default by stating our assumption that the patient will comply, and used loss aversion by pointing out that each day represents a victory (which would be “lost” if the next day the patient behaves differently4).

There remains, though, a number of issues with relying too much on nudging to change behavior in this case.  First, we are talking about highly ingrained, essentially intrinsic human behavior.  Nudging people towards the choice of becoming organ donors is one thing but trying to nudge them away from behavior that is instinctive can be something quite different.1  

Secondly, nudging techniques can certainly help and should be used by all healthcare professionals, but mass communications can only go so far. Although they are very efficient on broad society on the mid / long run, nudging techniques might be less so when immediate results are required. Extraordinary action, such as confinement or other compulsory measures, might be decreed by public authorities to compel people into a desired behavior. Such public decision also awake a higher sentiment of gravity of the situation, bringing additional efficacy to behavior change.

So, when behavior change needs to be drastic and quick as is the case with COVID-19, compelling public measures need to be instituted. It is impossible to teach a population on short notice to stop, for example, shaking hands, when this act is a part of established social norms.  On the other hand, if compelling measures can be efficient in the short term, in the long term, nudging techniques should be used to modify norms and modify the behavior of the population in preparation for future potential pandemics. Nudging remains a powerful and indispensable tool that helps shape behavior on a broad social scale.

To go further:

Ajzen, Icek.  From Intentions to Actions: A Theory of Planned Behavior . In Action Control, 1139. SSSP Springer Series in Social Psychology, 1985.

Ajzen, Icek. Constructing a theory of planned behavior questionnaire, 2006.

Kahneman, Daniel. Thinking, Fast and Slow. London: Penguin Books, 2012.

Lally, Phillippa, Cornelia H. M. van Jaarsveld, Henry W. W. Potts, et Jane Wardle.  How Are Habits Formed: Modelling Habit Formation in the Real World. European Journal of Social Psychology 40, no 6 (octobre 2010): 9981009. doi:10.1002/ejsp.674.

Reach, Gérard.  A novel conceptual framework for understanding the mechanism of adherence to long term therapies . Patient preference and adherence 2 (2008): 7.

Riekert, Kristin A., Judith K. Ockene, et Lori Pbert, éd. Handbook of health behavior change. 4th edition. New York, NY: Springer Publishing Company, LLC, 2014.

Fishbein, Martin, et Marco C. Yzer.  Using theory to design effective health behavior interventions. Communication theory 13, no 2 (2003): 164–183.

Elster, Jon. Social Norms and Economic Theory. The Journal of Economic Perspectives 3, no 4 (1989): 99117.

Tarquinio, C., et M.-P. Tarquinio. L’observance thérapeutique: déterminants et modèles théoriques. Pratiques Psychologiques 13, no 1 (mars 2007): 119. doi:10.1016/j.prps.2006.09.005.

Thaler, Richard H., and Cass R. Sunstein. Nudge: Improving Decisions about Health, Wealth, and Happiness. Rev. and expanded ed. New York: Penguin Books, 2009.


  1. Thaler, Richard H., and Cass R. Sunstein. Nudge: Improving Decisions about Health, Wealth, and Happiness. Rev. and expanded ed. New York: Penguin Books, 2009.
  2. Kahneman, Daniel. Thinking, Fast and Slow. London: Penguin Books, 2012.
  3. ICC-WHO Joint Statement: An unprecedented private sector call to action to tackle COVID-19, World Health Organization, Statement of 16/03/2020
  4. Kahneman, D. & Tversky, A. (1979). “Prospect Theory: An Analysis of Decision under Risk”. Econometrica. 47 (4): 263–291. CiteSeerX doi:10.2307/1914185. JSTOR 1914185.