Yeah, I've worked in two shops where every developer was on guard for themselves, those were not fun situations. I can usually figure out I am in such a scenario when I ask someone if they would mind helping me by reviewing or talking through how I solved a somewhat prickly problem. If they instantly turn me down in such a way that to suggest "Not my problem, not my concern" I usually tack that onto a mental score sheet for deciding not to renew or extend my contract.

Usually I am more receptive towards teams that have a final interview stage where all of the other dev's weigh in. I've avoided some fairly toxic places because of that step.