Research suggests that certain patterns of nonverbal and vocal cues are somewhat systematically associated with deceptive communication. Included among these cues are behaviors symptomatic of underlying anxiety and of reticence or withdrawal, excessive behaviors, behaviors signaling negative affect, incongruous responses, and behaviors suggesting vagueness. When asked to report those nonverbal cues signaling deceptive messages, observers mention many of the actual behaviors associated with deceptive encoding. Thus, observer difficulty in detecting deception stems primarily from inability to detect or to interpret nonverbal cues, rather than from ignorance or misinformation about the cues themselves. However, observers are not successful in detecting deception perpetrated by strangers via different modes transmitting varying amounts of nonverbal and vocal behavior. One table and about 80 references are supplied. (Author summary modified)