I've spent a great deal of my career working with people. I must say that I've gotten along quite well. Except for "she", I can't recall too many people whom I would label "enemies". However, I'm struggling with the group of people where I work that don't seem to want to participate in the concept of "teamwork".
In general terms, being a member of a team means that there is a common goal. In most sports, the goal is to win the game, match, or tournament. Having been a coach I can tell you all that a single person who spells the word "team" with an "I" can really bring a team to its knees. It's really not that different in the IT world. When you are a consultant, contractor, or employee, we all get our goals from our leadership and we try to make the goals happen within a specific time frame.
Not so recently where I work. For some reason, some people on the team have decided not to cooperate. They have no professional ethic, they are disrespectful, and they have their own set of goals that aren't necessarily in line with the rest of the organizations. It's sad. I guess they are selfish and only have their own best interests at heart. But, if they participated in the team dynamic, they would be part of a larger success. Win as a team, lose as a team. It doesn't matter if you think you spell it with an "I", the team falls when those around it are marching to a different drum.