ABSTRACT
In 1976, the Journal of Personality and Social Psychology published a field experiment conducted by Middlemist and his colleagues (Middlemist, Knowles, & Matter, 1976). The investigators hypothesized that the presence of others is arousing. The field in which the study took place was a men’s public bathroom. In the control condition, the unwitting participant used the only urinal not closed for cleaning. In the first experimental condition, one confederate stood at the urinal next to the one the unwitting participant was using. In the second experimental condition, the confederate stood one urinal away. The question is whether the presence of a confederate who coactively engaged in private elimination would increase physiological arousal. If the answer is yes, the arousal would cause contraction in the muscles at the exit from the bladder, and so delay the onset of urination. The delay and the tension would then cause the urine stream to be faster and therefore to persist for a shorter time. To test the hypothesis, the experimenter hid in a cubicle behind the urinals, balanced a little periscope on some books under the door, and directed it upward so that the participant’s urinal was visible. From there, he observed and recorded the delay and persistence of urination accurately with a timepiece. The evidence confirms the investigators’ hypothesis.
