You think this is exclusive to Yale?
No it's universal, but I'd speculate there's a correlation between the degree to which privilege can isolate people from a result oriented culture and the amount of nonsense they will engage in, so ivy league colleges like Yale are an ideal cloud chamber in which to precipitate these kinds of circle jerks. Take the Skull & Bones society. It's the same structure. People reinforcing one another's beliefs.
It's kids in a sandbox playing make believe. They're playing the Holier Than Thou variation of Mine's Better Than Yours. It's not just Yalies, or college kids in general, or even SJWs. You get the same social dynamic from political conservatives. Office workers. Construction site lunch rooms. Model train enthusiasts. Even bodybuilders playing "We're Better Than Them." You name it. Most uninterrupted interactions yield social gameplay which pays off to those who further the game and vilifies those who don't. Since no one has interrupted these kids for years at a time, the group's cohesion depends strongly on the game continuing so you've got this borderline Lord of the Flies conform-or-else thing happening there.
People get shitty if you don't play. They get even shittier if you mock their game by playing sarcastically. They don't like having their mutually agreed upon basis for interaction made fun of. I generally get kicked out of the sandbox by the other kids for being a spoilsport, and a boring one at that.
Aside: This is why I find female conversation especially interesting. It's a gross generalization but men are usually trying to get something accomplished so are task oriented, whereas women's interactions center on finding and reinforcing some kind of alliance, so a badly executed conversation between females is like a wreck in slow motion. Beats Nascar any day. Successful gameplay being a goal in itself is probably also why females are more strongly represented in SJW circles. Or any kind of circle. Sewing circles. Male interactions are abbreviated by finishing something. Without a focus for the conversation, women don't have a social finish line. They just meander all over the place like this post, except fascinating.
https://en.wikipedia.org/wiki/Games_People_Play_(book)
