Why you need to know this: if one colleague is courteous with everybody else and difficult with you, and nobody quite believes you, this explains what the evidence says is going on and what to do before you decide what that colleague is.
Almost everybody who has worked for long enough has met this colleague. They answer everybody else’s messages within the hour and yours by the end of the week; they are warm in the meeting and curt in the corridor, and when you mention it to anybody, the reply is some version of really? They have always been fine with me. People reach two conclusions: that the colleague is a particular kind of person, or that the problem is them.
The research on mistreatment at work supports neither conclusion as a starting point. Incivility, meaning rude, dismissive or discourteous treatment whose intent to harm is unclear, is common: a 2026 review reports that about three in four employees have experienced it (Magley, Kabat-Farr, Malcore & Walsh, 2026), and it is also aimed: a pooling of 57 studies found that what predicts aggression depends on who it is aimed at (Hershcovis et al., 2007), and a study of coworker pairs in three separate samples found that how uncivil people are to each other varies substantially from pair to pair, over and above how uncivil each person tends to be with everybody (Taylor, Locklear, Kluemper & Lu, 2022).
The first surprise is who gets picked. Among 4,874 university staff in 339 work groups, higher performers were more likely to be on the receiving end, and a second study of 217 employees in 67 groups traced that to envy in the rest of the group (Kim & Glomb, 2014). Supervisors show both ends: anger toward those they see as performing poorly, and envy toward those performing well (Li, Law, Zhang & Yan, 2024).
The second is where the dark traits sit. In a study of 172 employees, the people who reported bullying others scored high on Machiavellianism and psychopathy, and the people on the receiving end did not (Dåderman & Ragnestål-Impola, 2019). And in 225 teams, supervisors high in Machiavellianism were more abusive only when they believed their position gave them power (Wisse & Sleebos, 2016).
The third is that it can become mutual. In a study that followed employees through two working weeks, incivility received earlier in a day was followed by incivility given later the same day (Rosen, Koopman, Gabriel & Johnson, 2016). A difficult pair can become a pair in which both people are difficult, without either of them choosing it.
None of this licenses a verdict on the colleague or on you. What it offers is a sequence: check whether the pattern really is aimed at you before naming it, break your own half of any spiral, change the structure of contact rather than the temperature, and treat mistreatment that follows a line of sex, ethnicity or status as a conduct matter rather than a personality clash, because a 2013 study of three organisations found exactly that pattern (Cortina, Kabat-Farr, Leskinen, Huerta & Magley, 2013).