You Did Not Choose Your Colleagues, and That Changes What You Owe Them
Advice about work relationships is mostly borrowed from friendship, and the borrowing causes specific problems. A different starting point.
Most advice about getting on with colleagues is friendship advice in a work setting: be interested in them, find common ground, build rapport. It is not wrong and it produces a specific confusion, because the defining fact about a colleague is that neither of you chose the other, and everything about a friendship depends on choice.

What follows from being assigned rather than chosen, in my experience running teams of volunteers — which are assigned in the same way, minus the salary — is that the obligations are narrower and clearer than friendship’s, and pretending otherwise makes people worse at both.
You owe a colleague reliability, plain communication, and not making their job harder than it needs to be. You do not owe them your interest in their personal life, your availability outside agreed hours, or the assumption of good faith beyond what their behaviour supports. That third one is the one that gets people, because friendship-derived advice says assume the best, and in a relationship you did not choose and cannot leave, assuming the best indefinitely in the face of contrary evidence is not generosity. It is a failure to update.
The practical consequence I have seen most often is people treating a work problem as a relationship problem. Someone consistently delivers late; the friendship frame says the issue is that you have not built enough rapport, so you try harder socially, and nothing changes because lateness is not a rapport problem. The work frame says name the specific behaviour and its effect once, plainly, and see what happens. That conversation is short and unpleasant and works about two-thirds of the time in my experience, which is a far better rate than months of building rapport.
The reverse error is also common and I have made it: treating a genuine friendship that formed at work as a work relationship. It happens, they are real, and they are the thing people miss most when they leave a job. What I would say about those is that they need converting the moment one of you leaves — a specific plan within a fortnight — because the container is gone and without one they end, warmly and completely, within about eight months.
The other thing that follows from being assigned is that you are allowed to simply not click with someone and for that to be nobody’s failure. In a group of twenty there will be two or three people whose company you would never choose. Friendship advice frames this as a problem to be solved; I think the correct response is to be scrupulously decent, reliable and pleasant, and to not take it personally that there is nothing more there. I have worked closely and well with people I would not have a drink with, and the work was not diminished by it.
Where the friendship frame does earn its place is in the small things that are genuinely reciprocal: remembering that someone’s mother has been ill, noticing when a person is having a bad week, covering something without being asked. Those are not rapport-building; they are just how you treat a person you are near for forty hours a week. The difference is that they are offered rather than transacted, and the moment they are done as technique everybody can tell.



