And then when you went to middle school, those same people were there. Even if you went to a different school in a different state, as I did, they were the same types of people. The social mix didn't really change.
And then you went to high school, and maybe college, and the groups were there again. Some people crossed into different groups, but the same types of people were still there. Some people were jerks, and some were cool. Some people were smart, some were dumb. Some spent their lives trying to get laid. Some worshipped their cars. Some tracked who was going out with who.
And then it was out into the big bad working world. Slightly different categories, but only barely. There's the guy who does the very least he can to get by, and the girls who gossip about who's seeing who, and the girl who does whatever's possible to take credit for everything, and so on.
And when you switch jobs, you know what's at that new job? The exact sample people. Even in an entirely new career, it's the same thing. The same people you love at your old job will be at the new one. The same people you hate at your old job will be at the new one.
Bottom line: It's pointless to leave a job because of something other than what your job is. Someone you can't stand? Get over it and do your job. You're a fool if you think that the co-workers you have at your new job are going to be any better than the co-workers you have now.
If you're going to leave for a negative reason (i.e. not because of a better position), it should be limited to either not enjoying the work, or because of an ethical problem you have (i.e. being asked to falsify sales reports to vendors). Anything else is just job churn, 'cause I'll lay even money that before long you'll run into the same person conflict that you had in the old job, and then what do you do? Run to another new job?
Mind you, I'm talking about individual persons here, not institutional. Some jobs are going to have different mixes of people. The workforce for a software publisher is going to be different than for a McDonald's than for the US Army than for The Gap. I'm talking about running away from individuals.
People are the most malleable part of any job. Your co-workers come and go regularly. The only stable part of your work is YOU. You have the choice of how to handle the conflict, to handle the suboptimal part of your day. Don't let the bastards get you down.