Loving people, really loving them for themselves, while I recommend it, is a true and royal pain in the ass.

Groups have moods and personalities. There is the "drink the Kool-Aid mode",

You know, my social groups use the phrase "drink the Kool-Aid" fairly commonly, for someone who's bought into an idea/technology/company so far that they've lost the ability to clearly see its flaws. On the one hand, perhaps it's crass, since 913 people died, including 276 children, and we're generally talking about people being too enthusiastic about Oracle or Microsoft. On the other hand, hopefully the idiom keeps alive the memory of such a horrible incident and the sorts of mental states that can lead to it.

where everyone thinks the same thing (groupthink), but then there is a richer, more complex dynamic of a group of individuals rationally together for a purpose. My canonical example is college a cappella groups: the Skidmore Dynamics, today, have much the same group personality as when they were founded in 1995, mostly through the self-selection process of replacing graduating or quitting members. That's what you'd expect, but the more surprising part comes with a large influx of members into the group: groups normally average ten to fifteen students, so this means a high-percentage replacement, of 5 or 7. In those cases, the new people and group personality both influence each other. A group that is historically arrogant will become somewhat less arrogant, but the new members, integrating with the group's reputation and the habits of the veteran members, also become more arrogant, at least with the group. I watched this happen many times with groups including my own, and the continuity of the group personality never fails to amaze me. I'm sure social psychologists have words for it; I don't.