> I'd argue that good judgement of how reliable different pieces of information are is one of the most important aspects of intelligence.I agree. In fact, while civilization has ameliorated many of the challenges to individual survival, that aspect has become much more acute.
> A smart individual can distill valuable information even when surrounded by propaganda while a dumb individual will still fall for a lot of propaganda even when surrounded by mostly correct information since they can't tell the difference.
I think that several things are going on here.
First, it has become increasingly difficult to distill and discern truth, in part because it has become more difficult to figure out what level of scrutiny any particular proposition merits.
Many of the proxies we have for trustworthiness are social and often co-opted by competing interests.
This also applies to the trustworthiness of scrutinizers.
I mean, anthropogenic global climate change is fairly well established at this point, at least in terms of mechanism and direction, but if you apply enough paranoia and squirt a bit you can discern a vested interest for doomsayers to minimize errors and collude in producing a false consensus.
The general public is more-or-less aware that enough money can either create a false consensus or cast 'reasonable' doubt at will (eg. globalization will lower unemployment and grow the economy, and smoking doesn't cause cancer).
So, given all that, a lot of people just fall back on tribalism (or more like "team-sport-ism") when allocating their limited time and attention in deciding who or what to trust vs. scrutinize, since no matter where you look you can find conflicts of interest (eg. the profit motive explains overprescription of OxiContin, so why shouldn't it explain pharma collusion to give people cancer and sideline cheap natural cures?).
It isn't that truth extraction is too hard per-se, it's the meta-task of choosing reliable sources as your starting point that has become impossible.