Iodine, Illusions, and Ill-Advised Medical Diagnoses

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More Iodine, More IQ Points

According to a new NBER paper, adding iodine in the drinking water of the US produced a dramatic increase in IQ levels.

Before iodine was in drinking water, most people were iodine-deficient. If you're iodine-deficient, you won't think as clearly, will be more likely to get sick in other ways, and generally won't be your best self.

What's truly jaw-dropping is just how effective iodine is. Specifically, in iodine-deificent areas, IQ rose by a full 15 (!!!) points. Considering the average IQ score is 100, that is a tremendous effect size. So many areas of the US were deficient that this boost produced a 3.5% increase in the national IQ average.

It's remarkable how the smallest of policy decisions can have the biggest effects.

More Neurons (if you stay out of the cubicle)

When I was in school, I was taught that humans couldn't grow new neurons (a.k.a brain cells) after adolescence. Maybe you were too.

This was great for anti-drug campaigns ("don't smoke pot or you'll permanently ruin your brain!") but it turns out to be total bullshit.

The source of this bullshit: bad experiments. Specifically, the studies were done on animals living in cages and other restricted environments. In these environments, the animals didn't grow any new brain cells.

Recent studies suggest that as soon as you take those animals out of the cage and put them back in a rich, natural environment, their brains start growing again. It's crazy to me that it took so long to figure this out.

The upshot for humans: if you spend most of your time in monotonous, repetitive environments - like a cubicle - your brain will literally stop growing. In times of quarantine, it is vitally important to get outside, see new things, and have new experiences. And if you can't, you should just buy a virtual reality headset - it's good for your brain!

More Familiarity, More Trust (even of lies)

People made many millions of dollars betting on Joe Biden to win the US election. But these people didn't bet on Biden in advance - they bet on him well after the election was already over.

They bet after every news station had called it, after every relevant state had certified the result. Yet they still were able to pocket a ~12% return on a guaranteed fact. Thanks to my buddy Brian Feldman, I was one of these people.

I've been trying to figure out why Trump supporters would continue to bet so heavily after it was clear they would lose. One possible explanation is the Illusory Truth Effect.

In short: Psychologists have found that the more you hear something repeated, the more likely you are to believe it. Critically, this happens even if you already know what you're hearing is a lie.

The effect works because when people assess truth, they rely on whether the information agrees with their understanding or whether it feels familiar. Researchers discovered that familiarity can overpower rationality, if you hear the same falsehood enough.

In other words, "fake news" works not just by giving people what they want to hear. It works through sheer repetition.

In this specific case, I'm glad to have profited off Trump supporters who have poor media diets. But in general, knowing about the Illusory Truth Effect makes me more pessimistic that any substantive change is possible for these types of people.

More Dsylexia, More Inequality

According to the latest research, there's no single disease called "dyslexia". Rather, there's a bunch of different reasons why kids have trouble reading, and we bunch them all together under one umbrella.

This might not seem like a big deal - doctors do roughly the same thing with the term "cancer" - but it actually has a significant downside.

Since there's no clearly defined way to diagnosis dsylexia beyond "this smart kid is having trouble reading", doctors have a lot of latitude in who receives the diagnosis and who doesn't. In practice, it's mostly wealthy kids who get called "dsylexic", while poor kids with the same reading difficulties get no diagnosis at all.

Being formally diagnosed means access to learning therapists and special schools. By the same token, not getting diagnosed means missing out on those benefits.

The rest of the world should do what forward thinking counties in the UK have done: eliminate the diagnosis of dsylexia and provide help to any kid that has trouble reading, whether a doctor has validated it or not.

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"Your twenties are always an apprenticeship, but you don't always know what for." – Jan Houtema

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