8 Participants, including Dr Rosenhan himself, entered 12 different asylums across the United States in the early 1960's. Each asylum varied in size, funding and age. Rosenhan asked participants to pretend to suffer from a mental disorder and present themselves to the asylum for admission.
Once inside participants told the psychiatrists fake names and addresses. They also told them that they were hearing voices saying words such as empty, thud and hollow.
Help me doc
You're clearly schizophrenic
Each participant was accepted into the hospital. Participants then tried to tell the staff that they were sane and that they should be allowed to leave. However participants were not discharged.
Look I'm a Dr conducting research!
That's just one of your symptoms Mr Jenkins.
One participant had to stay for over 52 days. In this time they were able to record information, some of the other real patients worked out that they were not really mentally ill, this is something that the doctors could not work out
You're not crazy!
This patient indicates pathological writing behaviour.
These findings show that the asylum system is biased, unreliable and not well managed at the time.
There was an experiment 2 in which another prominent asylum said that this would not happen in their hospital. Rosenhan told them that they would be sent pseudo-patients, and the staff had to rate on a scale of one to ten if they thought a patient was a fake. 83 patients total were said to be fake. In fact none were. Proving that no-one can prove that someone is sane or insane, not even a psychiatrist.