As far as I can tell, people's vulnerability to memetic hazards that drive some people but not others insane should be very predictable. Granted that there are problems with retrospectively changing one's outlook to try and defend against some of them, it shouldn't be too hard to test someone to see if they already have appropriate cached response defenses up without exposing them to the idea itself.
Today's post, Why Are Individual IQ Differences OK? was originally published on 26 October 2007. A summary (taken from the LW wiki):
Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was No One Knows What Science Doesn't Know, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.