I would probably focus on evidence; why you need evidence to locate hypotheses, conservation of expected evidence, absence of evidence as evidence of absence](http://lesswrong.com/lw/ih/absence_of_evidence_is_evidence_of_absence/. Add in the ability to make beliefs pay rent and what makes a real explanation, and how to avoid treating science as a piece of attire or genre, and you'll have covered some of the primary bases people tend to use to signal rather than apply intelligence.
Hi, next month I'm going to be doing an hour long presentation on rationality to Mensa members. It needs to be rather introductory, since High QI != Rationality and most of them are not familiar with the concepts discussed here.
I'm planning to talk about what rationality is (any good quotes?), what is the difference between the brain and the conscience, why being rational does not mean having a perfect willpower, some common and easily avoided fallacies (sunk cost, scope insensitivity).
I did a search on the site for this kind of introductory posts and have quite a large pool of interesting arguments to touch. Does anyone have any suggestion on which topics should be included, any pointers to interesting posts that should be summarized or used as source material, etc.?