Middlemist et al. (1976) conducted a study in which a men's public restroom was set up so that confederates could invade a participant's personal space. In the restroom, there were three urinals. In the close distance condition, a confederate appearing to urinate was stationed at the middle urinal, and a "Don't use" sign accompanied by a bucket and a sponge was placed on the rightmost urinal. In the moderate distance condition, the confederate stood at the rightmost urinal and the bucket and sign were placed in front of the middle urinal. In the control condition, there was no confederate in the restroom. The researchers were interested in the time it took to initiate urination, as well as how long the participants would urinate. An observer was hidden in one of the toilet stalls. The observer used a "periscope" embedded in some books on the floor to check on urination. The periscope allowed the observer to see the stream of urine. The observer started two stopwatches when a participant stepped up to the urinal, stopped one when urination began, and stopped the other when urination was terminated. The results showed that when a confederate was close, participants took longer to urinate and urinated for less time compared to participants in the other conditions.

Middlemist, R. D., Knowles, E. S., & Matter, C. (1976). Personal space invasions in the lavoratory: Suggestive evidence for arousal. Journal of Personality and Social Psychology, 33, 541-546.

Identify at least 3ethical concerns with this study and explain why this is a ethical concern.