Why we see 'them' as a monolith and 'us' as individuals

Ideas & Philosophy · Published 17 October 2026 Swipe more like this →

In short: Have you ever noticed how people in your own circle seem like unique individuals, while people in another group all seem to act the same? This isn't just a lack of imagination; it is a documented psychological phenomenon where we perceive out-groups as more similar to one another than our own diverse community.

The out-group homogeneity effect describes the tendency to view members of an outside group as more alike, while perceiving our own in-group as diverse. This bias leads to overgeneralized stereotypes because we overestimate the similarity of 'them' based on central tendencies or typical attributes. For example, a study involving 90 sorority members found that every single participant judged their own group as more dissimilar than the other groups they were asked to evaluate.

Psychologists debate whether this is a cognitive error or an adaptive social perception. One theory suggests it stems from how we process information: we may focus on differences within our own group (the 'me' vs. 'others in the group' dynamic) but only attend to the differences between groups when looking outward. Self-categorization theory explains this by noting that in an intergroup context, we may experience 'depersonalization,' where we attend only to the differences between 'us' and 'them,' making the members of the other group appear uniform.

However, the effect can shift based on motivation and identity. Social identity theory suggests that people—especially those in minority groups—might actually emphasize in-group homogeneity to establish a positive, distinct identity and protect self-esteem against perceived threats. Conversely, some research suggests that people use their ratings of group variability simply to express how much they believe a group possesses specific characteristics, a process that may occur independently of social motivations or the amount of personal information we have about the members.

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