Fear specifically causes heightened arousal in liars, which manifests in more frequent blinking, pupil dilation, speech disturbances, and a higher pitched voice. The liars that experience guilt have been shown to make attempts at putting distance between themselves and the deceptive communication, producing “nonimmediacy cues” These can be verbal or physical, including speaking in more indirect ways and showing an inability to maintain eye contact with their conversation partners. Another cue for detecting deceptive speech is the tone of the speech itself. Streeter, Krauss, Geller, Olson, and Apple (1977) have assessed that fear and anger, two emotions widely associated with deception, cause greater arousal than grief or indifference, and note that the amount of stress one feels is directly related to the frequency of the voice.