Summary: Researchers investigated how human brains weigh choices that affect other people, especially when preferences conflict. In a controlled experiment, participants learned and compared food preferences—both their own and those of others—and used that information to make decisions intended to benefit the entire group.
Using brain imaging and detailed behavioral tasks, the team found that neural reward systems track personal preferences and also encode the preferences of others on a common scale. This shared neural representation supports decisions that maximize collective welfare rather than just individual gain, illuminating how the brain supports social, utilitarian choices.
Key Facts:
- Participants learned and integrated their own food preferences with the preferences of others through observation and rating tasks, with choices designed to reveal how preferences are compared for group benefit.
- Activity in brain regions linked to reward processing—most notably the ventromedial prefrontal cortex—reflected not only one’s own subjective values but also the inferred preferences of others.
- The neural patterns used to represent others’ preferences were the same patterns that represented utilitarian welfare, suggesting the brain repurposes reward-related circuitry to compare and sum subjective values across people.
Source: SfN
Decisions that affect other people require weighing multiple options and choosing those that improve collective outcomes.
Whether selecting a gift for a friend, casting a vote for public office, or designing policies to improve societal welfare, we routinely consider how our choices will influence others. To better understand the neural mechanisms behind such decisions, researchers from Ludwig Maximilian University Munich and the University of Zurich collaborated on a study led by Alexander Soutschek.
Their findings appear in the Journal of Neuroscience.
In the experiment, human volunteers fasted for four hours before testing to increase motivation for food-based choices. Over several task phases, participants rated how much they liked different food items, learned to associate symbols with quantities of food, and observed other people making food choices. Importantly, the preferences participants observed were intentionally set to be opposite to their own, creating situations with conflicting desires.
In the final phase—described as a welfare maximization task—participants decided how to allocate different quantities of food between themselves and the other person whose tastes opposed theirs. This setup required participants to integrate and compare divergent preferences and to make choices that could maximize the combined welfare of both individuals.
Behavioral results showed that participants could infer others’ preferences from observed choices and represent these preferences alongside their own. Rather than favoring self-interested allocations, participants often chose distributions that increased total welfare, indicating an ability to perform cross-person preference comparisons.
Neuroimaging and multivariate analyses revealed a key neural substrate for this ability. Distributed activity patterns in the ventromedial prefrontal cortex (VMPFC)—a region long linked to reward and value representation—encoded the strength of other people’s preferences. Strikingly, the same neural code in the VMPFC also represented utilitarian welfare, meaning the summed, group-level value used to guide welfare-maximizing choices.
These results suggest that the brain reuses reward-processing mechanisms to compare subjective values across individuals and to compute aggregate outcomes that support utilitarian decisions. In other words, the neural machinery that helps us evaluate rewards for ourselves appears capable of mapping and summing others’ values to inform decisions that benefit the group.
Overall, the study provides direct evidence that humans can learn and scale others’ preferences, represent them on a common neural scale, and use this information to make choices that aim to maximize collective welfare—even when preferences conflict.
About this social neuroscience research news
Author: Alexander Soutschek
Source: SfN
Contact: Alexander Soutschek – SfN
Image: The image is credited to Neuroscience News
Original Research: Closed access. “Neural reward representations enable utilitarian welfare maximization” by Alexander Soutschek et al., Journal of Neuroscience
Abstract
Neural reward representations enable utilitarian welfare maximization
From deciding which meal to prepare for guests to weighing the economic costs and environmental benefits of climate policy, we regularly consider how our actions affect other people’s well-being. Preferences and tastes can differ widely across individuals, and utilitarian decisions require comparing these subjective values to maximize the total welfare of a group.
This study demonstrates that both female and male participants can learn others’ preferences by observing their choices and represent those preferences on a shared scale to guide utilitarian decisions. Multivariate support vector regression analyses showed that distributed activity in the VMPFC—a brain region associated with reward processing—encoded the strength of others’ preferences. Importantly, the same neural patterns in the VMPFC represented utilitarian welfare, indicating that the brain uses a common code for estimating individual preferences and the summed welfare they produce.
Taken together, these findings indicate that humans can behave as if maximizing utilitarian welfare by relying on a specific utility representation, and that the brain implements such choices by repurposing reward-processing neural circuits to represent and combine the values of others.