Toffee and Risk: Scientists Discover Why People Who Crave Sweets Make More Impulsive Choices

© iStock

Having a sweet tooth may be linked not only to eating habits but also to the way people make decisions. Researchers at HSE University have found that people with a preference for sweet foods tend to behave more impulsively—not because they want immediate rewards, but because they are less willing to tolerate uncertainty. These findings may help improve treatments for addiction. The study findings have been published in Frontiers in Psychology.

Impulsive choice—preference for a smaller immediate reward over a larger delayed one—is considered an important behavioural marker of self-control. However, the mechanisms underlying this tendency are still not fully understood. Previous research has shown that people with greater sensitivity to rewards are more likely to make impulsive choices, but the reasons behind this relationship have remained unclear.

Researchers at the HSE Institute for Cognitive Neuroscience experimentally investigated the relationship between impulsivity and reward sensitivity using preference for sweet tastes as an indicator.

In experiments involving 149 young participants, the researchers used the standardised Kampov-Polevoy sweet-taste preference test to classify participants as either sweet likers—those who preferred the most concentrated sucrose solution—or sweet dislikers. The participants then completed a series of tasks assessing risk aversion and impulsivity, in which they chose between smaller and larger rewards, as well as between immediate and delayed rewards.

Sweet likers were significantly more likely to choose a smaller but guaranteed reward, demonstrating greater risk aversion. In the impulsivity task, they also tended to prefer a smaller immediate reward over a larger delayed one. However, when both options involved a delay, they were more willing to wait for the larger reward. After the researchers accounted for each participant's level of risk aversion, the apparent impulsivity of the sweet likers largely disappeared.

The researchers suggest that sweet likers choose immediate rewards not because they are unwilling to wait, but because delayed rewards always involve uncertainty, which they tend to avoid.

According to the authors, this effect may be linked to the brain’s opioid system. Sweet taste preference is associated with the activity of receptors that are involved not only in experiencing pleasure but also in assessing threats and uncertainty. If individuals with a strong preference for sweet tastes have heightened sensitivity in this system, they may not only derive greater pleasure from rewards but also perceive potential losses or uncertainty more intensely.

Anna Davidovich

'We are used to thinking of impulsivity as an inability to delay gratification. However, our findings point to a different mechanism: choosing a smaller immediate reward may stem from a desire to avoid uncertainty rather than from a desire to receive a reward as quickly as possible. This changes our understanding of the nature of impulsive behaviour,' says the study’s lead author, Anna Davidovich, Research Assistant at the Centre for Cognition & Decision Making of the HSE Institute for Cognitive Neuroscience.

The findings open up new perspectives for understanding the biological basis of impulsivity and risk-taking behaviour. In the future, the researchers plan to investigate the neurobiological mechanisms underlying these effects using EEG and computational models of decision-making. They believe that this research could contribute to improving the diagnosis and treatment of various addictions.

The study was conducted with support from HSE University's Basic Research Programme.