@Lili Said
People will always group themselves. Racism is one example, but not he only one by far.
On this board somewhere is a thread about heavy metal music, and this poster who started it was getting rather upset at people confusing these
extremely narrowed down sub-genre's of heavy metal, it was rather stunning to read through actually. I mean, imagine if everyone only listened to heavy metal music, itself a sub-genre of rock. That's pretty specific, you'd think people had settled on one type of music, that they'd all come to an agreement, the matter was settled. Oh no. Is it death metal, satan metal, goth metal? And god forbid you confuse one for another! People will always differentiate, categorize and subgroup themselves, no matter how similar or different they start out.
It's also a matter of people feeling a need to feel like they belong within a specific group of people, this allows them to feel both unique and an accepted part of society at the same time. This need is so strong in fact that there are people who intentionally infect themselves with HIV, they are called "bug chasers", they want to be part of a relatively rare but still highly supportive group of society, those who are HIV+.
So as long as people exist, there will be cliques, and there will be conflict. It will never end as long as humans are human.
Yes, in a sense I believe that a little bit of conflict is good for in that it signifies as you mentioned above that there is difference in this world. Afterall, what would life be without a challenge or adversity? Makes it all the more fun in my opinion. But people deliberly infecting themselves with HIV? Now that's a new one for me