Until challenged with an alternative reason that makes any sense
Those who are unable to lie (e.g., because of involuntary behavioral cues) can credibly signal when they are telling the truth (through a lack of those involuntary cues); those who are good liars have no such credible signal. Related.
Today's post, The Comedy of Behaviorism was originally published on 02 August 2008. 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 Detached Lever Fallacy, 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.