It is easy to imagine that we can run out of willpower, and many people will certainly recognise themselves in the description.
Postdoctoral fellow Thomas de Haan, The Choice Lab
All out of willpower
Willpower is a finite resource, or so many people believe, that can run out under pressure.
An NHH researcher has tested whether people become more suggestible when they are drained of willpower.
Willpower can become depleted when a person is subjected to major challenges or difficult tasks. It is a finite resource that can be exhausted. This is one of the theories on willpower that researchers in several different disciplines, including behavioural economics, are taking as the starting point for their studies.
A number of researchers believe they have proven Freud's "ego depletion".
Give in to temptation
"It is easy to imagine that we can run out of willpower, and many people will certainly recognise themselves in the description," says Thomas de Haan, postdoctoral fellow at The Choice Lab – NHH's behaviour research team.
If you are mentally exhausted after having concentrated on demanding tasks, you may have less self-control if you are exposed to influence afterwards. The mental energy that regulates your thoughts and impulses is drained.
"Intuitively, this seems correct, but for researchers it is difficult to study the phenomenon scientifically. It is complicated to pinpoint what is really happening, but I was curious and wanted to see if we could learn anything from this kind of study," says de Haan.
Buy a car when you are on top form
He and his colleague Roel van Veldhuizen tested whether people are more easily "framed" after they have performed demanding tasks (see the reference below).
"Most people are swayed by how information is presented (framing effects): the question in this study was whether our decisions are easier to influence when our self-control is low," says de Haan
An example of framing in daily life is buying a new car.
After a demanding day at work, your willpower may be low, and customers can be easier to influence. Salespeople prefer to approach customers when they have lower self-control. Conversely, customers will benefit from transferring important decisions to a time of day when they have enough willpower to make more rational decisions. This will impair the salesperson's attempt to "dress up" the message to get the customer to commit to buy.
More suggestible?
Researchers at The Choice Lab performed several laboratory experiments. In one of them, 104 participants took the Stroop test, a well-known psychological test. Half of the participants were shown a series of colour words ("red", "blue", etc.) written in a different font colour than the word indicated; for example, the word "red" written in blue.
The task was to remember the colour of the printed word. The other half were given a far easier task: they simply had to remember colours that matched the words.
Override impulses
It might sound fairly simple, but remembering the font colour when the content indicates a different colour is actually quite difficult. And that is the point. The participants have to struggle to remember the illogical connections. They need to override the impulse to read the colour word, otherwise they will not manage to remember the font colour.
In keeping with the theory of willpower depletion, several rounds of this test will lead to weakening of the participants' self-control. The NHH researcher's hypothesis was that this could affect the participants' ability to perform new tasks given to them.
In theory, the people who took the concentration-intensive Stroop test ought to have been more easily influenced than the people who had performed basic intuitive tasks.
Everyone is "framed"
"Overall, we found no differences between the participants," says de Haan.
Previous studies have given varying results.
"This may indicate that willpower depletion does not have such a great effect. The effect is more limited and less consistent than has been previously thought."
De Haan was surprised by the findings, but he has not quite given up on his hypothesis that willpower depletion makes people more suggestible.
"The idea that you are more easily influenced by context when you are tired and mentally drained is intuitive, and I still think it is interesting. But it is difficult to prove in research. Depletion of willpower is subtle. It goes without saying that it is difficult to pin down," the researcher concludes.