Confounding influences on police detection of suspiciousness

The social psychological literature had shown wide acceptance by the police of the use of nonverbal behaviors such as smiles, speech disruptions, gaze aversion, and hand gestures as cues to deceptive or suspicious activity by criminal suspects. Current police investigative training also reinforces these beliefs. The present study analyzed the influence of race and emotional agitation level on the frequency with which these ‘suspicious’ nonverbal behaviors are displayed. Reviewing 120 videotaped police-citizen interactions of a noncriminal nature involving law-abiding citizens, the results suggested that level of emotional agitation had a weak but significant influence on the frequency with which two of these nonverbal behaviors were displayed. Race also had a significant influence that ranged from moderate to strong, as African-American and Hispanic citizens displayed significantly higher levels than Caucasians of behaviors thought of as ‘suspicious’ by police officers.