In our society, defecation involves anindividual in activity which is defined as inconsistent withthe cleanliness and purity standards expressed in many of ourperformances. Such activity also causes the individual todisarrange his clothing and to 'go out of play," that is, todrop from his face the expressive mask that he employs inface-to-face interaction. At the same time ic becomes difficultfor him to reassemble his personal front should the need toenter into interaction suddenly occur. Perhaps that is areason why toilet doors in our society have locks on them.
Erving Goffman, The Presentation of Self in Everyday Life
philosophy, sociology