From flawed self-assessment to blatant whoppers: the utility of voluntary and involuntary behavior in detecting deception.

Malingering occupies a range on a continuum from biased self-perception to conscious, deliberate, serious lies. One aspect of this continuum is the element of self-conscious or deliberate control. Suggestions from Darwin's writings concerning the role of voluntary and involuntary activation of the facial muscles are examined and illustrated with data from a 40 year program of research on deception. The impact of the voluntary-involuntary distinction on the appearance, timing, symmetry and cohesion of facial expressions of emotion is explained. Data relevant to changes in vocal and gestural aspects of demeanor in honest and deceptive behavior are also reviewed. The relevance of these laboratory-based findings on the voluntary control of nonverbal behavior in assessing some types of malingering is discussed. Copyright (c) 2006 John Wiley & Sons, Ltd.