This study was designed to see if the presence of E was sufficient to produce “demand characteristics” in a psychological experiment. Two physiological indices, electromyogram and heart rate, measured performance of a task, i.e., not to respond to a tone. E's presence facilitated S's ability not to respond as indicated by EMG. E's presence had a facilitating effect and “demand characteristics” of psychological experimentation appear to exist.
Do demand characteristics contribute to minimal ingroup preferences?