Dr David Rosenhan was a psychologist from Stanford University. In 1972 David and some other volunteers, who also happened to be psychologists and psychiatrists, feigned hallucinations in order to get admitted to psychiatric hospitals across the USA.

Once they were admitted to the hospitals they acted completely sane and normal. They wanted to see if they would be correctly diagnosed as being sane.

But not a single staff member of any of the hospitals noticed. Instead, normal sane behaviour was interpreted as insane behaviour.

If they took notes it was considered “pathological writing behaviour”. If they queued early for lunch it was described as “exhibiting oral-acquisition symptoms”.

Then the experiment began to get serious. The researchers couldn’t get out of the hospitals because the staff were convinced they were insane.

Even when the lawyers got involved the hospitals would release them. The researchers had to admit to the diagnosis they were given, tell the staff they felt well now and promise to take anti-psychotic drugs on release.

The research was presented in the journal “Science” in 1973 with the title “On being sane in insane places”. 

It caused quite a stir. One teaching hospital refused to accept it and insisted that properly trained doctors would not make these mistakes.

So David Rosenhan issued a challenge to the hospital. How many of the fake or impostor patients could the hospital detect over the next three months?

Over the period the hospital had seen 118 patients. They reported that 42 were fakes and another 41 were suspected as fakes.

But Rosenhan didn’t send a single fake patent at all.

So the hospital was misdiagnosing insane people as sane. When before they were diagnosing sane people as insane.

It shows that we see what we expect to see. 

A study at Oak School in the 1960s showed that labelling students as “gifted” changed the way teachers interacted with them. 

Students were given a standard IQ test, which researchers called the Harvard Test of Inflected Acquisition. A very official-sounding name designed to give the impression that high scores will predict high academic achievement.

But the researchers didn’t take the actual top 20 per cent, instead, they randomly selected 20 per cent of the students and informed the teachers that these students had scored in the top 20 per cent. The children had no idea of their gifted label and conducted themselves as they usually would – some staring out the window, others full of excuses and of course diligent students were all included in the 20 per cent.

At the end of the year, the students took the IQ test again and sure enough, the students labelled as being in the top 20 per cent had, in fact, increased their IQ scores by the largest amount.

The teachers’ consciously or unconsciously given additional help or attention to the students labelled as gifted.

We see what we expect to see or what we want to see. I think we all have a confirmation bias.

Confirmation bias is when we don’t look at a subject objectively, instead, we look for evidence that confirms what we already believe.

It’s hard to find objective information on synthetic meat for instance. The authors of articles are usually for or against. I’m wondering if their bias is affecting how they portray the facts.

The same is true for politics. We tend to look at the team we support as being right or having the best policies.

Charlie Munger has a good quote relating to confirmation bias. “Ask yourself what are the arguments on the other side. It’s bad to have an opinion you’re proud of if you can’t state the arguments for the other side better than your opponents.”

That’s actually really hard to do. 

If you support Bernie Sanders for instance, can you state the arguments for voting for Trump better than an actual Trump voter?

It’s difficult, but its a really useful exercise to swap sides and argue against the very thing you believe. 

If you do it honestly you end up understanding the topic better. I think we should all want to understand the world better.