Today, will you socialise after work or stay at home? Will you do exercise or relax and watch tv?

How do you decide whether its worth making extra effort? And why is it that some days this is easier than others?

Previous research has shown that when deciding whether to do something effortful, people weigh up whether they think the benefits outweight the costs. However, in the real-world people seem to vary a lot in how willing they are to make effort over time. Some days we feel full of energy and motivation, and choose to make more effort whereas other days we lack motivation and choose to avoid effort. We do not have a good scientific understanding of what causes our choices to change like this, mostly because typically studies measure people’s decision making on just one single day.

We investigated how people’s motivation changes using a study with smartphone games as people went about their daily life. We sent people notifications asking them to tell us how motivated, happy and tired they felt as they went about their daily life, and asked them to play an effort-based decision-making game on their phones. The game asks people to choose whether they want to exert more effort for more reward and using computational modelling we can estimate how they do this in order to generate their choices.

We found that how motivated people felt in the moment was directly linked to how much effort they were willing to make, and this effect was even stronger for people who reported lower motivation overall. Our computational model showed that the reason people were more willing to make effort was because their sensitivity to reward increased. Since there were many smartphone notifications in the study, we were also able to test if the changes in how motivated people felt led to changes in reward sensitivity in the future, or the other way around. We found that how motivated people felt (several hours in the past) even predicted increased reward sensitivity in the future.

These results are especially interesting because they show that we can use smartphone games to track how people’s choices fluctuate over time, and actually that decision-making is more variable than researchers have previously assumed. It is also great that we could test people as they went about their normal day to day life, because this means we can access more diverse samples of people (without needing them to come into our lab). This type of research may help us to better understand how day-to-day changes in decision-making can fall into dysfunctional and disabling patterns in conditions like depression, anxiety and obsessive-compulsive disorder.

Hewitt, S. R., Norbury, A., Huys, Q. J., & Hauser, T. U. (2024, August 12). Real-world fluctuations in motivation drive effort-based choices. https://doi.org/10.31234/osf.io/w3x7d

Preprint: https://osf.io/preprints/psyarxiv/w3x7d

Play the game on your phone: https://ema-motivation.web.app/