We conducted a study on 3691 people to empirically test 40 claims about IQ (including claims made in academia and by the general public)! Here are some of our most important findings (see the link at the bottom of this thread for all 40 results):
🧵 Question 1: Is IQ actually normally distributed (i.e., is its histogram a "bell curve") or is that just forced on it based on the way it's constructed?

Answer: On our general population sample, the distribution fits a bell curve well, even with no adjustments!

You're absolutely right. About all of it. The big stuff, the weird stuff, the "nobody-gets-this" stuff. Every belief you hold is, against all odds, completely correct. I know I said before that you were wrong, but it was I who was wrong! Here's proof:
🧵 1/14) Your subconscious runs Bayesian inference constantly in the background. If an idea survives your relentless evidence updates, the posterior odds confirm it's rational. Your convictions passed the most brutal audit possible: reality itself.

LGBTQ+ identity has been doubling from generation to generation. Gallup finds:
• 2% of Boomers
• 5% of Gen X
• 10% of Millennials
• 22% of Gen Z
identify as LGBTQ+

What's caused this rise?

At Clearer Thinking, we investigated, and the answer really surprised me:
🧵⬇️ The surface-level mystery has a simple answer: bisexual identification. Most of the increase in LGBTQ+ identity is from younger generations identifying more as bi. But this raises a deeper mystery:

Why are younger generations identifying as bisexual at such higher rates?

1/ Is the idea of IQ legit or total B.S.? With the replication crisis in social science, it's worth asking this since a number of major psychology findings didn't hold up under scrutiny.

To find out, at Clearer Thinking, we ran a massive study...🧵 2/ We tested thousands of people performing random subsets of 62 diverse cognitive tasks (vocab, math, logic, pattern recognition, reaction time, games, memorization, mental rotation, language learning, etc.).

The Dunning-Kruger Effect is one of the most famous psychology findings. It's the idea that people of low competence/ability overestimate their ability. But is it REAL? At Clearer Thinking, we investigated (with surprising twists and turns): 🧵 First off, "Dunning-Kruger" is sometimes used to reference a 2nd related idea: that high-competence people *underestimate* their ability (the opposite of low-competence people)

We'll explore both ideas.

What was found in the original study about these effects?

Being one of history's most successful entrepreneurs is quite a different skill than making predictions about the future. So, I wondered how accurate Mսs𐔘's predictions are. I spent hours finding as many of them as I could, aiming to be as even-handed as possible:
🧵 Overall, I identified 50 predictions about the future he'd made for which it was confirmable whether they'd been correct. I skipped predictions that were too ambiguous to judge.

So, how did he do?

20% were correct predictions, and 80% were wrong.

How good or bad is this?

If you're convinced that astrology doesn't work at all (e.g., by studies like ours, where we tested 152 astrologers and found they were no better than random chance at matching people to charts), that raises an interesting question: why do astrologers believe astrology works? 🧵 1st hypothesis: they know astrology doesn’t work and lie for profit. But that seems very unlikely: many rely on it themselves and do it for friends/family. While surely there are some charlatans, most seem totally and genuinely convinced. So, what else could explain their belief?

Does astrology work? We tested the ability of 152 astrologers to see if they could demonstrate genuine astrological skill.

Here is how the study was designed and what we found (including a result that really surprised me):

🧵 Back in January, we ran a study trying to predict 37 facts about people's lives using their astrological sun signs (whether they are Pisces, Aries, etc.) While personality tests were able to predict these facts decently well, sun signs couldn't predict even a single 1 of them...

There’s a really interesting debate raging in the field of genetics about how heritable different human traits are. It could end up overturning 100 years of research:
🧵 First off, what is heritability? It’s the fraction of the variance of a trait (in a particular population) that’s caused by genetic differences.

Everyone agrees that height is at least fairly heritable since, in most populations, much of the variation is attributable to genes.

Are there false memories that many people share (i.e., a "Mandela Effect")? For instance, is it true that people systematically misremember which of these is the actual "Mr. Monopoly" man? We recently ran a replication of a study designed to test these claims:

[megathread]🧵 Before I get into the results of the study, here's a pop quiz. See if you can tell which of these is real and which is a collective delusion (the answers are at the bottom of the thread):

(1 of 6) Which one is the real C-3PO?

How genetically heritable are human traits such as height, physical health, mental health, education, religiosity, conservatism, IQ, and personality, and what do these heritabilities actually mean?

[heritability megathread] 🧵 We all know that some things are determined by our genetics (nature) and some by our environment (e.g., nurture). But most things are somewhere in between.

Where do things like physical health, mental health, and personality fall on this spectrum from nature to nurture?

Important but often overlooked: when groups differ a small amount in their means, they may differ *dramatically* in their tails.

For instance, in a personality study, we found males to have a little bit lower average compassion score than females (1.4 vs. 2)

[tails thread] 🧵 Small differences like this in averages are typically not noticeable or important. Most people are not in the tails.

If you knew only someone's compassion level and had to guess their sex from it, you'd be wrong more than one-third of the time (predicting optimally)!

Sometimes, groups are genuinely found to differ a bit, on average. For instance, it may be found that men are a bit more dishonest than women or that Chinese kids outperform Americans at math.

At this point, people tend to go off the rails in one of 2 ways:

🧵 Group 1: Oversimplifiers. These are people who greatly exaggerate the difference.

They ignore that the gap is (i) small and (ii) only a difference in averages (not applying to all individuals). They go around saying it's proven that "X's are like this" (e.g., men are liars).

Four widely believed numbers that claim to be scientific but which actually aren't:

[bullshit 'scientific' numbers megathread🧵] 1) "10,000 hours of practice are required to achieve world-class performance in anything."

This false idea was popularized by Malcolm Gladwell in "Outliers." The scientist whose work it's based on (Anders Ericsson) has explained it's a misinterpretation of his work. What's true?

Before Twitter locked down its API, I started an analysis to figure out (empirically) "the 'greatest' tweets ever from intellectuals."

Here's an abbreviated version based on the analysis I was able to do:

[24 'greatest' tweets from intellectuals megathread] 🧵 1) 🥇 Award for the best "adorable personification of an animal" goes to @juliagalef

Fake experts are everywhere on the internet. How do you spot a reliable expert and differentiate them from unreliable fakes?

Here are 12 signs to look for, each of which can provide evidence of a proclaimed "experts" reliability:

[expertise megathread] 🧵 1) 🦉They have deep factual knowledge

Experts possess extensive knowledge of relevant information, demonstrating a command of the (non-disputed) facts. It's far easier to tell if someone knows the non-disputed facts than to evaluate whether they are right on the disputed points

Can you tell whether a correlation between two things is meaningful from a scatter plot? Well, take a look at this example (see image).

Do you see a meaningful relationship between x and y?

Take a look at the thread below for the "answer": The scatter plot above reflects a correlation of r=0.2.

Okay, but is that a "meaningful" correlation?

Whether a correlation is "meaningful" depends on two things:

What are IQ test questions that people get right at different IQ levels (e.g., 100, 110, 120, 130, etc.)? Some folks have asked me to pull up data about this from a big study we ran on intelligence. These are all very rough approximations, but here you go:

IQ question thread 🧵 A question indicative of (very approximately) 100 IQ

Are people who make more money happier? Let me tell you a tale with many twists and turns about the scientific investigation of this question - along with a surprise ending that you're unlikely to uncover even if you read the papers on this topic

Income/happiness mega thread 🧵 One way to measure "happiness" is to ask questions like "How satisfied are you with your life?" or "On a ladder numbered 0 to 10, where 10 is the best possible life for you, and 0 is the worst, where do you place yourself?"

Questions like these measure "life satisfaction."

Gaslighting, where someone causes another person to doubt their feelings and senses, can cause psychological damage.

There's an opposite thing, though, that can also be damaging. As far as I know, it has no name. I call it Lightgassing.

Here's how it lightgassing works:
🧵 Lightgassing is when one person agrees with or validates another person's false beliefs or misconceptions in order to be supportive.

Unlike gaslighting, a tactic of jerks and abusers, lightgassing is an (unintentionally harmful) tactic of friends and supporters.

A worldview typically consists of at minimum 4 components involving answers to these questions:

1) What is good?
2) Where do good and bad come from?
3) Who deserves the good?
4) How can you do good or be good?

Here's a mega thread to help you understand 10 common worldviews:
🧵 2) New Atheists