Compulsive traits are tendencies to repeat patterned behaviours. They are often seen in psychiatric conditions such as obsessive-compulsive disorder (OCD), addiction and eating disorders. However, these behaviours exist on a spectrum and are present to an extent across the population, even in people without mental health conditions.
Neuroscientists at King’s used an online video game played by 2000 people to examine the relationship between compulsive traits and different types of decision making.
The new study linked compulsive traits to a type of decision-making strategy, in which people repeat habitual behaviours rather than relying on long-term plans. Crucially, people who were more compulsive were also more uncertain about the outcomes of long-term plans, making them more likely to rely on habits.
Researchers compared the choices in the video game from participants to two different mathematical models: one based on a planning-heavy strategy and the other based on a more habitual strategy. The models also could track how certain participants were about the future consequences in the planning-heavy strategy.
Using these models, the data showed that people who scored higher for compulsive traits were both more prone to the habitual strategy and had greater uncertainty about consequences in the planning strategy.
“We found that people with more compulsive traits may rely on habits not because they can’t plan, but because they feel less certain about how their actions will play out. This gives us a more precise mechanistic explanation for patterns that have been observed for years.” – Sirichat Sookud, first author on the study.
To plan or not to plan?
People regularly make the type of decision where they can choose between a habitual or a planning-based strategy.
“After a long day of work, you immediately head to the freezer and take out a frozen pizza, almost as if without thinking. If your goal was to lower your cholesterol, you might have chosen to make a salad instead, because in the long-term you want to improve your health. Your more frequent choice, the frozen pizza, is a simpler choice that doesn’t benefit your general health goals,” explains Dr Toby Wise, Senior Research FellowNeuroscience, King’s College London.
This kind of goal-directed decision making (accounting for outcomes far off in the future) is only possible if you appreciate that eating healthily will reduce your cholesterol, ultimately improving your health. In decision making theory, this is referred to as possessing an “internal model” of how your actions lead to more distant consequences.
“If you want to eat healthier, you need to weigh up your options and mentally simulate the impact each choice will have on your long-term health. This type of decision making is often called ‘model-based’. The pizza is more of a habitual choice and doesn’t require any sort of forward planning. This type of decision is often called ‘model-free’,” says Dr Wise.
Previous studies have linked differences in goal-directed decision-making to multiple psychiatric conditions such as obsessive-compulsive disorder (OCD) and addiction. Symptoms in these disorders may arise from people choosing habitual (model-free) choices instead of goal-directed (model-based) choices. For example, someone may repeatedly check whether a door has been locked because it made them feel less distressed last time they did it, leading it to become a habitually repeated action.
The new study highlights further the role of uncertainty in these choices.
“If you are uncertain about what the future may hold, it is more likely you will reach for the choice you have made in the past,” comments Dr Wise. “Our data show that people who are more compulsive are feeling more uncertain about the future, which may explain why they shy away from model-based planning strategies in favour of habitual behaviours.”
Using video games to study behaviour
The study used a video game to understand how people make different types of choices. While being visually appealing and deployable online (enabling easy recruitment of 2000 participants), this video game contained mathematical principles that could untangle different decision-making strategies.
“Using online video games like this one makes it possible measure psychological processes remotely in huge numbers of people, providing incredible datasets and opening participation in research to a wider audience,” explains Dr Wise.
Based on a popular psychological paradigm, called the two-step task, the game can untangle if players are making choices with the future in mind. The game used in this study added another component to the task: uncertainty.
In the game, players had to shoot aliens using a cannon that could fire pink or purple balls. Balls were stored in two containers that they had to choose between, each with a mix of pink or purple balls.
Success in the game depended on two things: realising that the numbers of pink and purple balls in the two containers were related to each other (building an internal model), and learning that some balls might explode before hitting the target (uncertainty).
To hit the most aliens, players needed to combine their knowledge about the colours of the balls in each container and the chances of each colour of ball exploding mid-air.
“While this is quite a complicated process, we actually do this kind of future-oriented planning every day, and so it’s something that is quite straightforward to measure in a game,” says Dr Wise.
This research was supported by a Wellcome Trust Career Development Award.
Biological Psychiatry Cognitive Neuroscience and Neuroimaging
Observational study
People
Impaired Goal-Directed Planning in Transdiagnostic Compulsivity Is Explained by Uncertainty About Learned Task Structure
5-Mar-2026
The authors report no biomedical financial interests or potential conflicts of interest.