The Natural Experiment: In four of the hospitals the pseudo patients carried out an observation of behaviour of staff towards patients that illustrate the experience of being hospitalised on a psychiatric ward. The pseudo patients approached a staff member with a request, and they asked them for example ‘…when am I likely to be discharged?’. In order to compare the results Rosenhan carried out a similar study at Stanford University with students asking university staff a simple question.
Results: All of the pseudo patients disliked the experience and wished to be discharged immediately. None of the pseudo patients was detected and all but one. They were diagnosed with schizophrenia and were eventually discharged with a diagnosis of 'schizophrenia in remission' This diagnosis was made without one clear symptom of this disorder. They remained in hospital for 7 to 52 days (average 19 days), Visitors to the pseudo patients observed ‘no serious behavioural consequences'. Although they were not detected by the staff, many of the other patients suspected their sanity (35 out of the 118 patients voiced their suspicions). Some patients voiced their suspicions very vigorously for example ‘You’re not crazy. You’re a journalist, or a professor. You’re checking up on the hospital’.The pseudo patients’ normal behaviours were often seen as aspects of their supposed illness. For example, nursing records for three of the pseudo patients showed that their writing was seen as an aspect of their pathological behaviour. 'Patient engages in writing behaviour'. Rosenhan notes that there is an enormous overlap in the behaviours of the sane and the insane. We all feel depressed sometimes, have moods, become angry and so forth, but in the context of a psychiatric hospital, these everyday human experiences and behaviours were interpreted as pathological.