Society is made up of individuals. If you can demonstrate that individuals are irrational, then you have a better chance at claiming that the society is too. Yudkowsky wrote about the sanity waterline rather late when he had already covered a lot of other topics and I think this was intentional.
You can't just start from the assumption that society would be more rational if rationality was taught at school. You'd also need evidence that rationality can be taught to a lot of average people. I don't think such evidence exists. Whatever taken out from the curriculum might be replaced by something completely ineffective.
Of course, if changing the curriculum would make some of the smarter individuals more rational, and leave the average student with nothing, the result might still be a net positive. This argument wouldn't convince anyone professing egalitarianism however.
Individual benefits are far easier to sell than societal benefits. They're easier to imagine, examples are available, they're near rather than far, self interest is inherently motivating, and your reader won't be mindkilled by politics. If you can get the reader to accept the individual benefits, then you might be able to extrapolate a bit from there.
The title of this post is misleading, since you're not illustrating anything but asking for advice.
You can't just start from the assumption that society would be more rational if rationality was taught at school.
It could actually make things worse. It could put the whole society into a huge valley of bad rationality.
On the other hand, maybe that's exactly where the society is now.
Does anyone know of a good article that illustrates how society is generally irrational, and how making society more rational would have huge benefits, because it'd be a very high level action?
I'm writing an essay about how to improve education, and one of my proposals is that a core part of the curriculum should be rationality. I believe that doing this would have huge benefits to society, and want to explain why I think this, but I'm having trouble. Any thoughts?
Edit: Part of Raising the Sanity Waterline talks about common ways in which people are irrational. However, they're all links to longer Less Wrong articles. Preferably, I'd like to illustrate it in a few sentences/paragraphs.