It is possible things have changed substantially over the years, but when I was there and definitely for quite a long time after, attending parties outside of campus was very rare at Caltech. Parties on campus were not common either, and most of them were parties within a house.

Caltech undergraduate life is kind of like being in a science monastery. It's not merely a school of nerds. It's a school of the people who nerds think are too nerdy.

On the STEM vs. non-STEM issue, I'm not treating "fresh out of high school engineering students as rational actors and everybody else as ignorant buffoons".

Everyone, without exception, needs to rely on expert opinion in some matters. No one has the time and capacity to become expert themselves in all fields that are relevant to all important decisions we have to make in our lives.

Sadly, in many of the areas where we have to rely on experts there are many with financial or ideological interests in getting people to not listen to the experts. This results in people being presented with conflicting opinions all purporting to be from or backed by experts in the relevant areas.

One of the best ways to resolve such a situation is, if you can do it, is to learn enough about the subject yourself to be able to look at the same information and methods that were used to produce the conflicting opinions and determine which came from actual experts and which did not.

In this one very particular area, namely determining if a particular set of behavioral rules and procedures to prevent a particular community from getting COVID and to limit its spread within that community if it does get in is scientifically justified, STEM students are going to be more likely to be able to do the type of evaluation described in the prior paragraph than are non-STEM students.

Would you say I'm being a "STEMlord" if I said Caltech students were more likely than, say, students in Julliard's piano bachelor's degree program to be able to evaluate evaluate whether someone making a claim about the theoretical upper limit on the efficiency of a classical thermodynamic engine is correct?

It works the other way, too. There are plenty of areas where I'd expect that Julliard piano student to be way better than any Caltech student at evaluating conflicting purported experts. It is just that those areas don't happen to be relevant to the specific problem of convincing a group of people that specific anti-COVID measures are correct.