Let's talk about the glass delusion, the Middle Ages' bout with a mass psychogenic illness marked by people believing they were made of glass.
Glass was a valuable commodity in Europe. It was primarily owned by the noble and well-to-do, and it had a notable purpose in alchemy.
Its perception as the technology of the time was as one that's both fragile and valuable, like the nobility.
Glass was the relatively novel technology people knew, and they knew things could be transmuted into glass. Delusional people also thought transmutation could affect them.
Take King Charles VI.
He truly believed his body was made of glass.
This delusion was such that Charles felt he had to build his life around it.
He had iron rods fastened into his clothing to hold him up, and he didn't allow his advisors to approach him, lest they accidentally shatter him.
This illness set in during his twenties.
The age when his psychotic bouts started is remarkably consistent with when the illness starts today.
Were he alive today, he probably would have been prescribed antipsychotics for his condition.
But Charles was alive long before his condition was understood.
He also wasn't its only sufferer. As alchemy's popularity grew, more people started to suffer the glass delusion.
They understood glass as fragile, and themselves as fragile, and they acted out that script.
For the well-off, the delusion was treated as legitimate. Many nobles came to wear padded buttocks.
But in one case, in Saint Germain, a doctor took a man who thought his butt was made of glass and beat him until he stopped believing in the delusion.
Apparently that worked.
Amusingly, in Rene Descartes' Meditations on First Philosophy, he remarked on the glass delusion and used it as an example of how people can see the world in totally different ways.
Of course, he did say that the perception was insane.
Fast forward to the 19th century and factories are beginning to dot the landscape of Europe.
With the change in popular technology, people's delusions followed suit.
With industry, the delusions became industrial. People imagined they were being influenced by vast machines.
Patients who presented with this belief in intricate, far off machines that controlled their actions and influenced their lives could never explain how they worked.
Just as people didn't know how they became glass, they didn't get how machines were affecting them.
Factories influenced the world, machines could obviously influence us, thus...
Schizophrenics' delusions are tailored to what they vaguely know, and they learn about those half-baked delusions from others, the times, etc.
Consider exorcism. Its modern script came from a movie!
People today know about parasites, chronic pain, post-viral conditions, toxic poisoning, and more, and they have an amazing tool for finding and promoting related scripts:
The internet!
Thousands of people today believe they have a skin condition called Morgellons.
It's not real.
They just believe they're developing sores and lesions, and hairs are sprouting from them, but they're really picking themselves raw and getting freaked out by cotton fibers.
The sufferers from this condition are deeply unwell, and they spread their unwellness to other people through posting about their condition online.
People know about all the requisite concepts, and they see something on themselves and imagine it's a real symptom.
But it's not.
There are no demons, there's no Morgellons, people cannot be made of glass, and there's no big machine out there influencing people and miraculously disappearing the moment those concepts go out of fashion and get replaced by other ones with nary a cure invented.
And this keeps happening!
People are always inventing new conditions or imagining they're afflicted by something real when they're not, by reading into symptoms and gaslighting themselves.
And they sometimes act incredibly mad in these bouts of belief.
A subset of people today seem vulnerable to scripts, and some seem to have always been vulnerable to it.
It makes you wonder: must psychotic people always be like this? And what can we do to cure them of their delusions?
I suggest we don't give in with padded buttocks.
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What predicts a successful educational intervention?
Unfortunately, the answer is not 'methodological propriety'; in fact, it's the opposite🧵
First up: home-made measures, a lack of randomization, and a study being published instead of unpublished predict larger effects.
It is *far* easier to cook the books with an in-house measure, and it's far harder for other researchers to evaluate what's going on because they definitionally cannot be familiar with it.
Additionally, smaller studies tend to have larger effects—a hallmark of publication bias!
Education, like many fields, clearly has a bias towards significant results.
Notice the extreme excess of results with p-values that are 'just significant'.
The pattern we see above should make you suspect if you realize this is happening.
Across five different large samples, the same pattern emerged:
Trans people tended to have multiple times higher rates of autism.
In addition to higher autism rates, when looking at non-autistic trans versus non-trans people, the trans people were consistently shifted towards showing more autistic traits.
In two of the available datasets, the autism result replicated across other psychiatric traits.
That is, trans people were also at an elevated risk of ADHD, bipolar disorder, depression, OCD, and schizophrenia, before and after making various adjustments.
Across 68,000 meta-analyses including over 700,000 effect size estimates, correcting for publication bias tended to:
- Markedly reduce effect sizes
- Markedly reduce the probability that there is an effect at all
Economics hardest hit:
Even this is perhaps too generous.
Recall that correcting for publication bias often produces effects that are still larger than the effects attained in subsequent large-scale replication studies.
A great example of this comes from priming studies.
Remember money priming, where simply seeing or handling money made people more selfish and better at business?
Those studies were stricken by publication bias, but preregistered studies totally failed to find a thing.
It argues that one of the reasons there was an East Asian growth miracle but not a South Asian one is human capital.
For centuries, South Asia has lagged on average human capital, whereas East Asia has done very well in all our records.
It's unsurprising when these things continue today.
We already know based on three separate instrumental variables strategies using quite old datapoints that human capital is causal for growth. That includes these numeracy measures from the distant past.
Where foreign visitors centuries ago thought China was remarkably equal and literate (both true!), they noticed that India had an elite upper crust accompanied by intense squalor.
One-in-two has a disability and/or a traumatic brain injury. One-in-five has psychosis. One-in-ten is schizophrenic. One-in-four is mentally retarded.
These facts have major consequences!
As I noted recently, the White House wants to bring back involuntary commitment.
They're probably in the right to call for that, since so many homeless are incapable of taking care of themselves, or at the very least, not hurting others.
Some people are mentally downtrodden because of injuries to the head.
Among the homeless, over half have suffered a TBI, compared to 12% of Americans. Just over 20% have a TBI-related disability, compared to about 2% of Americans.