Secrets and Lies: Involuntary Leakage in Deceptive Facial Expressions as a Function of Emotional Intensity

Darwin (1872) hypothesized that some facial muscle actions associated with emotion cannot be consciously inhibited, particularly when the to-be concealed emotion is strong. The present study investigated emotional “leakage” in deceptive facial expressions as a function of emotional intensity. Participants viewed low or high intensity disgusting, sad, frightening, and happy images, responding to each with a 5 s videotaped genuine or deceptive expression. Each 1/30 s frame of the 1,711 expressions (256,650 frames in total) was analyzed for the presence and duration of universal expressions. Results strongly supported the inhibition hypothesis. In general, emotional leakage lasted longer in both the upper and lower face during high-intensity masked, relative to low-intensity, masked expressions. High intensity emotion was more difficult to conceal than low intensity emotion during emotional neutralization, leading to a greater likelihood of emotional leakage in the upper face. The greatest and least amount of emotional leakage occurred during fearful and happiness expressions, respectively. Untrained observers were unable to discriminate real and false expressions above the level of chance.