The pain of being left out is something most of us have felt at some point in our lives, but new research suggests that the impact of exclusion isn’t just about the act itself—it’s also about who is doing the excluding. A study published in Scientific Reports has found that women’s brains react most intensely when they are excluded by unattractive, unfriendly women, revealing unexpected layers in how we perceive and react to social slights.
Social exclusion, a form of indirect aggression, is a powerful social signal that can significantly impact an individual’s emotional and psychological well-being. While previous research has extensively explored the effects of exclusion, this study aimed to dig deeper into how the characteristics of the excluder affect the experience of being excluded.
Women have historically and evolutionarily relied on social bonds for survival and cooperation, making them particularly sensitive to social rejection. The researchers were motivated by the idea that, in modern society, the pain of social exclusion might not only be about the act itself but also about the perceived social status of the person doing the excluding.
“I have been studying competition and aggression in women for years. This study represents an attempt to better understand women’s interpersonal interactions,” said study author Tracy Vaillancourt, a Tier 1 Canada Research Chair, full professor at the University of Ottawa, and author of the upcoming book Mean.
The study involved 87 undergraduate women aged 18 to 22, who were recruited from a university in Ottawa, Canada. The participants were primarily from the faculties of Social Sciences, Science, Health Sciences, and Arts. The sample was racially and ethnically diverse, with participants identifying as White, Black, South Asian, Middle Eastern, Asian, Latina, and Other.
The main experimental task was a virtual ball-tossing game known as Cyberball, a common tool used in psychology to study social exclusion. In this game, participants believe they are playing with other real people, but in reality, they are interacting with computer-controlled players. The participants were told that they would be competing against other women in the game and that their brain activity would be monitored using electroencephalography (EEG) to observe how they reacted when excluded by their peers.
When participants arrived at the lab, their photographs were taken against a neutral backdrop. These photographs were then used to create a set of virtual competitors who varied in terms of attractiveness and friendliness. The researchers used standardized images from the Chicago Face Database, which had been previously rated by independent raters for attractiveness. The competitors’ friendliness was manipulated by altering their facial expressions—some were smiling (friendly), while others were not (unfriendly).
Participants were randomly assigned to one of four conditions in which they would be excluded by different types of competitors: (1) attractive and friendly, (2) attractive and unfriendly, (3) unattractive and friendly, or (4) unattractive and unfriendly.
At the start of the experiment, participants were shown images of five potential competitors, each of whom was wearing a similar grey T-shirt to control for any influence of clothing. The competitors included two unattractive White women (either friendly or unfriendly), two attractive women (one Black and one White, either friendly or unfriendly), and an average-looking White woman who was smiling. Participants were asked to choose two competitors to play against.
The researchers manipulated the game so that it would appear to “crash” after the participants made their selections. When the game was restarted, participants were only given the option to play against two of the previously seen competitors — those who matched the condition to which they had been randomly assigned (e.g., attractive unfriendly or unattractive friendly). This manipulation maintained the cover story and ensured that participants believed they were genuinely interacting with real opponents.
During the game, participants would occasionally receive the ball from the virtual players, but as the game progressed, they were increasingly excluded, with the ball being passed exclusively between the other two players. This exclusion phase was the critical part of the experiment, as it allowed the researchers to observe how participants reacted both behaviorally and neurologically to being left out.
While participants played Cyberball, their brain activity was continuously monitored using EEG, which measures electrical activity in the brain. The researchers were particularly interested in a specific brainwave known as the P300 (P3) component, which is thought to reflect the brain’s response to significant or unexpected events. The P3 is often used in social neuroscience research to understand how people process social information.
“Women are highly attuned to cues of inclusion and exclusion,” Vaillancourt told PsyPost. “Our study confirms this — all participants noticed they were being excluded within 300 milliseconds.”
Contrary to what might be expected, the researchers found that participants’ brain responses were strongest when they were excluded by women who were both unattractive and unfriendly.
“We predicted that women would be most hurt by being excluded by attractive, unfriendly women because these are markers or social status in women,” Vaillancourt explained. “Women with higher social status should be able to inflict more harm than women with lower social status, hence our prediction. We found the opposite. Women were most bothered by being excluded by unattractive, unfriendly women.”
“This may be related to being offended by being rejected by someone they thought was inferior. Because people tend to overestimate their own level of attractiveness, it is likely that the women in our study thought the unattractive, unfriendly women who excluded them were out of line (e.g., ‘how dare she’ or ‘who does she think she is?’).”
After the game, participants completed a questionnaire designed to assess their subjective experience of exclusion. Participants also evaluated the competitors they had interacted with during the game.
The researchers found that participants tended to rate the women who excluded them more negatively across several dimensions. Excluders were seen as more rude, competitive, less attractive, less nice, and less happy than non-excluders. This aligns with previous research showing that people often retaliate against those who exclude them by judging them more harshly.
“Another interesting finding was that attractive unfriendly women were specifically punished for their exclusionary behavior,” Vaillancourt said. “The women in our study put them in their place by rating them lower on attractiveness even though they were objectively very attractive.”
The study provides detailed insights into the social dynamics of exclusion among women. But as with all research, there are some limitations. The sample consisted exclusively of young, university-attending women, which may limit the generalizability of the results to other populations. Additionally, the study did not include male participants or male photo stimuli, limiting the ability to examine potential gender differences in responses to social exclusion.
“My goal is to better understand indirect aggression and competition in women,” Vaillancourt said. “The next step is to replicate this study to see if the findings are robust across different social and age groups.”
The study, “Behavioral and neural responses to social exclusion in women: the role of facial attractiveness and friendliness,” was authored by Tracy Vaillancourt, Stefon van Noordt, Amanda Krygsman, Heather Brittain, Adam C. Davis, Iryna S. Palamarchuk, Steven Arnocky, Sidney J. Segalowitz, Michael J. Crowley, and Louis A. Schmidt.
