It seems like the common denominator to how much you like people is how much success you have "training" them in a sense. The main thing human and social intelligence helps with is an understanding of the fact that a) people aren't rational, b) people are selfish and c) people like acknowledgement.
Someone who wants an orderly, quick and efficient lifestyle will dislike most people because even with deeply ingrained training, they will often fail to meet expectations and may wildly defy them out of spite. Likewise, someone who enjoys spontaneous, off-the-cuff action will likely suffer fools rather gladly as they may often present a story for them to laugh about to themselves later. It might also aid their sanity to not have very high standards since nothing really phases somebody who enjoys idiocy one way or another.
As for training people, one must remember that humanity is a domesticated species by it's own hand. We've trained ourselves to work in herds and from there to grow societies so understanding that key part of sociology is key to understanding human nature. Without it you're left naive, with it and cynical, you become pessimistic and isolationist, with it and optimistic, you become cooperative and maybe cunning. Playing the game of society and becoming aware of it will leave those who take things very seriously dejected and castaway while those who decide to explore it will often find themselves amused sometimes even wholesomely. Plus, everyone wants to bully the guy who thinks too highly of himself. Whatever you make of this soapbox rant is up to you. It's all valid.
