Bias
Something I see a lot from the college-educated crowd is feigning a smart and wise approach to digesting information for a really stupid approach, usually in the form of unintentionally allowing biases into their stance on what somebody else said. I think this caused by people thinking they are less prone to bias or more intelligent than they actually are.
A clear example is people who will read something they have never heard before/don't think is credible, and so they do the "mature" thing, or their "due diligence," and research the person who wrote it, what others things they have written, and how they are received by other people. The biggest issue I have with people doing this is that, while this is something people are told to do in order to get a "bigger picture," and is often something that can legitimately be used to contextualize someone's arguments, most people aren't smart enough or aren't resistant to bias enough to know how to execute this research. And this includes me, if I'm being honest, which is why I try to minimize how much someone's history or personality influence my stance on what they're saying, even if it may leave me with a less clear idea of what the author meant at times.
I don't think this is something that should be taught to high schoolers and college students in the same way that you shouldn't teach a middle schooler about things at the same level as someone learned during their Ph.D. Anybody can merely regurgitate what they were told, thinking that they have learned something and are doing it correctly, but a very, very small number of those people will actually have a solid grasp of what the fuck they're actually doing. It's similar to somebody attempting to give first aid 10 years after their last first aid training; they're probably going to end up doing more harm than good. Allowing students to introduce confirmation bias in their research of a subject and pretending like it's genuine effort to understand something should be worked against.
It may be obvious that attacking the author of an article instead of the content of their writing is stupid, we're all told that every year we're in school, "ad hominem is a fallacy! Appeal to authority is a fallacy! Bandwagon is a fallacy!" But for some reason, it's acceptable to attack the stances the author takes and the public perception of them, as long as you word it in a way that sounds like you're smart. That is what I always see people doing once they learn "how to be smart," even professionals will make this mistake when discussing research, "they lied here, so how can you trust the integrity of their completely separated argument here." And maybe they have a point, maybe people can be generalized as liars and schemers with a more than acceptable rate of success, I'm just going off of what I believe to be unproductive since I have never seen somebody learn something by being told that so-and-so can't be trusted. Learning always comes best through a productive counter-argument, not somebody merely telling another that what they were told was wrong.