t turns out that your political views might influence more than your vote—they could even change how you feel about chocolate. A new study published in Personality and Social Psychology Bulletin reveals that people rate products less favorably when they are associated with their least-liked political party. The findings highlight how “political contamination” subtly shapes our everyday preferences in surprising ways.
Political polarization, especially “affective polarization,” has been increasing across the globe. This form of polarization refers to the tendency to feel positive toward one’s political in-group while harboring distrust or dislike toward the out-group.
While this dynamic has been well-studied in contexts like voting and media consumption, its effect on neutral, everyday decisions has received less attention. The researchers behind this new study set out to explore how even apolitical products can become contaminated by political associations.
“I have always been interested in moral social cognition, and my interest in political psychology probably began many years ago when I observed a post on social media where two famous Swedish politicians from ideologically distant parties posted a selfie at a soccer game,” said study author Arvid Erlandsson, a senior associate professor at Linköping University and member of the JEDI Lab.
“The caption read something like, ‘There are many issues where we disagree, but today we are happy to be on the same side.’ About half the comments were positive, but the other half were negative, with some people saying they could never cheer for a team supported by their least-liked politician. This inspired me to systematically investigate whether non-political things can be ‘contaminated’ simply by being liked by one’s political out-group.”
To investigate this, the researchers conducted a series of four experiments involving a total of 3,985 participants.
In the first experiment, participants evaluated clothing items before and after learning that these items were worn by politicians from either their most-liked or least-liked political parties. The researchers used photographs of well-known Swedish politicians dressed in formal attire, alongside non-political individuals in similar outfits as a control.
The findings revealed a clear “negative out-group effect”: clothes worn by politicians from participants’ least-liked parties were rated as less attractive after the political association was revealed. A smaller but significant “positive in-group effect” was also observed, with clothing linked to the participants’ most-liked politicians receiving higher ratings.
The second experiment expanded the investigation to chocolates, a less identity-relevant product. Participants rated a selection of chocolate brands before and after being told that certain chocolates were favored by supporters of their most-liked or least-liked political parties. This experiment also included a condition where chocolates were linked to bipartisan preferences, as well as a control group with no political association.
The results replicated the negative out-group effect: chocolates linked to the least-liked party were rated less favorably after the association was revealed. However, the positive in-group effect was less consistent, suggesting that political associations have a stronger impact when linked to disliked groups than to favored ones.
The third experiment examined real financial decisions. Participants were asked to allocate monetary donations to pairs of well-known Swedish charities. In the experimental conditions, participants were informed that certain charities were more popular among supporters of their most-liked or least-liked political parties.
The researchers found that participants consistently donated less to charities associated with their least-liked party, confirming the negative out-group effect. However, there was no significant increase in donations to charities linked to participants’ most-liked parties, reinforcing the asymmetry observed in the earlier studies.
“Data collection for Studies 2 and 3 coincided with the Russian invasion of Ukraine, which united all Swedish political parties in their condemnation of Russia,” Erlandsson told PsyPost. “The fact that we still observed these effects during this period of cross-partisan friendliness made me even more convinced of the robustness of the findings.”
The final experiment explored the role of public versus private decision-making. Participants were asked to choose between products—including chocolates, fruits, and charities—in scenarios where their choices were either private or observed by in-group members (represented by virtual avatars).
The findings showed that the negative out-group effect was amplified in public settings. Participants were even less likely to choose products associated with their least-liked party when they believed their choices were being observed by others from their political in-group. Interestingly, public observation did not enhance the positive in-group effect, which remained weak or absent in this study.
“Earlier studies on affective political polarization have shown that people distance themselves from the political out-group, such as when dating, evaluating candidates for a job, or attending Thanksgiving dinners,” Erlandsson explained. “Other studies have demonstrated the ‘party-over-policy effect,’ where the same policy is evaluated positively if proposed by the political in-group and negatively if proposed by the out-group. We also know that people sometimes boycott explicitly partisan brands or products, such as Twitter/X under Elon Musk, who openly endorses Donald Trump.”
“Our study extends these findings by showing a new manifestation of political polarization: distancing from neutral and apolitical products. Additionally, we find that this tendency is stronger in public than in private situations, suggesting that people may avoid products linked to their political out-group for reputational reasons.”
Interestingly, while the negative out-group effect was robust across all studies, the positive in-group effect was weaker and less consistent, appearing primarily in the context of aesthetic evaluations (experiment 1) and certain chocolate ratings (experiment 2).
“This was somewhat surprising but aligns with the idea that, unlike other social identities, a negative political identity (opposition to party X) is more prominent than a positive political identity (support for party Y),” Erlandsson said.
“In all studies, we tested whether the effects were politically symmetrical—similar for left-leaning and right-leaning participants—or asymmetrical. In three of the four studies, the results were symmetrical, suggesting that the tendency to distance oneself from politically contaminated products exists across partisan lines. In one study, however, rightist participants, but not leftist participants, showed a positive in-group effect, liking clothes worn by in-group politicians.”
While the findings strongly suggest that political polarization influences everyday choices, the study has some limitations. Conducted in Sweden, a country with a multi-party system, the results may differ in two-party systems like the United States. Additionally, the study focused on relatively neutral products; future research could explore whether similar effects occur with identity-relevant choices, such as favorite sports teams or cultural symbols.
“The research reported here was funded by the Swedish Research Council, which also supports several other related projects we are working on,” Erlandsson added. “We are currently studying political discrimination, politically motivated reasoning, openness to opposing views, and reactions to prosocial and antisocial behaviors toward political out-groups.”
The study, “Politically Contaminated Clothes, Chocolates, and Charities: Distancing From Neutral Products Liked by Out-Group or In-Group Partisans,” was authored by Arvid Erlandsson, Artur Nilsson, Jennifer Rosander, Rebecka Persson, and Leaf Van Boven.
