People who seem not to do it are mostly just more clever about it.
Hmm. This statement is troublesome because it falls into the category of "I expect you not to see evidence for X in case Y, so here's an excuse ahead of time!" type arguments.
And the rest of the paragraph is an argument that you should not only believe my claim, but convince your friends, too!
How convenient. :p
I would expect a witch to deny that they were signaling "not-witchness"
Abram Demski and Grognor
Much of rationality is pattern-matching. An article on lesswrong might point out a thing to look for. Noticing this thing changes your reasoning in some way. This essay is a list of things to look for. These things are all associated, but the reader should take care not to lump them together. Each dichotomy is distinct, and although the brain will tend to abstract them into some sort of yin/yang correlated mush, in reality they have a more complicated structure; some things may be similar, but if possible, try to focus on the complex interrelationships.