People with Power are Better Liars
Dana R. Carney, Andy J. Yap, Brian J. Lucas, & Pranjal H. Mehta
Columbia University

Abstract:  “Telling a lie is costly: emotionally, cognitively, and physiologically. Lie-tellers experience
negative emotions, cognitive impairment, physiological stress, and reveal this through nonverbal
cues. The emotional, cognitive, and physiological resources taxed by lying are enhanced by the
experience of social power. Power-holders enjoy positive emotions, increases in cognitive
function, and physiological resilience. This research tested and found that holding power buffers
individuals from the stressful event of telling a lie and leads to easy and effective deception. In
situations of high (vs. low) power, lie-tellers appear like truth-tellers emotionally, cognitively,
physiologically, and nonverbally.”

My guess on why this is true is that the leader may feel that his or her deception is for the good of the group and thus their sense of altruism prevents the expected stress of telling a lie.