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.
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.