THREAD: 12 Things Everyone Should Know About IQ

1. IQ is one of the most heritable psychological traits – that is, individual differences in IQ are strongly associated with individual differences in genes (at least in fairly typical modern environments). https://t.co/3XxzW9bxLE

2. The heritability of IQ *increases* from childhood to adulthood. Meanwhile, the effect of the shared environment largely fades away. In other words, when it comes to IQ, nature becomes more important as we get older, nurture less. https://t.co/UqtS1lpw3n
3. IQ scores have been increasing for the last century or so, a phenomenon known as the Flynn effect. https://t.co/sCZvCst3hw (N ≈ 4 million)

(Note that the Flynn effect shows that IQ isn't 100% genetic; it doesn't show that it's 100% environmental.)
4. IQ predicts many important real world outcomes.

For example, though far from perfect, IQ is the single-best predictor of job performance we have – much better than Emotional Intelligence, the Big Five, Grit, etc. https://t.co/rKUgKDAAVx https://t.co/DWbVI8QSU3
5. Higher IQ is associated with a lower risk of death from most causes, including cardiovascular disease, respiratory disease, most forms of cancer, homicide, suicide, and accident. https://t.co/PJjGNyeQRA (N = 728,160)
6. Higher IQ is associated with lower rates of most forms of mental illness. https://t.co/0jX1og7xHV (N = 1,049,663)
7. More generally, IQ tests are among the most reliable, predictive measures in psychology – one of the field's crowning achievements. https://t.co/a9z9GPQYuD

If IQ isn't a valid concept, no concept in psychology is valid.
8. Despite this, many people are allergic to the concept of IQ. Ironically, this includes many intellectuals. https://t.co/ThPkVT8apc
9. Perhaps as a result, there's some evidence that researchers are less likely to publish studies showing a link between IQ and grades – the reverse of the usual publication bias for positive findings. https://t.co/gTiKmmarTB; although see https://t.co/sYEgBnaJkO
10. The antipathy to IQ is unfortunate. IQ predicts all things good. Interventions to boost IQ (such as salt iodization) could greatly enhance human well-being. https://t.co/LHVqClN2kE

Conversely, IQ-denial could cause real harm by stalling the development of such interventions.
11. IQ testing has other potential benefits as well. One of my favourite studies of the last few years found that universal IQ screening boosts the number of poor, female, and minority students in gifted education. https://t.co/5at8wNjKe8

Figure: https://t.co/fogF8GyO8Z
12. Last but not least, here's a list of ten common myths about IQ. https://t.co/DOTDWhMoyS HT @StuartJRitchie

More from Steve Stewart-Williams

THREAD: My Top 12 Favourite Perceptual Illusions

1. A great example of how expectations guide perception.


2. The horizontal lines in this image are all parallel.
https://t.co/Y0o0hd8R15 HT @victoria1skye


3. The circles in this image are all the same colour. https://t.co/H4Prys8l0n


4. This isn't a GIF – the movement is all in your head.


5. This looks two photos of the same road, taken from different angles. But it’s just the same photo twice. https://t.co/pdq0iRynFw
39.1% of Democrats think that it's wrong to negatively stereotype people based on their place of birth... AND that Southerners are more racist. https://t.co/yp1hviLuBB


65.2% of Republicans think that people shouldn't be so easily offended... AND that Black Lives Matter is offensive.
https://t.co/znmVhqIaL8


64.6% of Democrats think that a woman has the right to do what she wants with her body... AND that selling organs should be illegal.

48.5% of Democrats think that a woman has the right to do what she wants with her body... AND that prostitution should be illegal.


57.9% of Republicans think that people should be free to express their opinions in the workplace... AND that athletes should not be allowed to sit or kneel during the national anthem. https://t.co/ds2ig1NJFr


Democrats: Men and women are equal in their talents and abilities. Also, women are superior. https://t.co/bEFSmqQguo

More from Life

You May Also Like

And here they are...

THE WINNERS OF THE 24 HOUR STARTUP CHALLENGE

Remember, this money is just fun. If you launched a product (or even attempted a launch) - you did something worth MUCH more than $1,000.

#24hrstartup

The winners 👇

#10

Lattes For Change - Skip a latte and save a life.

https://t.co/M75RAirZzs

@frantzfries built a platform where you can see how skipping your morning latte could do for the world.

A great product for a great cause.

Congrats Chris on winning $250!


#9

Instaland - Create amazing landing pages for your followers.

https://t.co/5KkveJTAsy

A team project! @bpmct and @BaileyPumfleet built a tool for social media influencers to create simple "swipe up" landing pages for followers.

Really impressive for 24 hours. Congrats!


#8

SayHenlo - Chat without distractions

https://t.co/og0B7gmkW6

Built by @DaltonEdwards, it's a platform for combatting conversation overload. This product was also coded exclusively from an iPad 😲

Dalton is a beast. I'm so excited he placed in the top 10.


#7

CoderStory - Learn to code from developers across the globe!

https://t.co/86Ay6nF4AY

Built by @jesswallaceuk, the project is focused on highlighting the experience of developers and people learning to code.

I wish this existed when I learned to code! Congrats on $250!!
“We don’t negotiate salaries” is a negotiation tactic.

Always. No, your company is not an exception.

A tactic I don’t appreciate at all because of how unfairly it penalizes low-leverage, junior employees, and those loyal enough not to question it, but that’s negotiation for you after all. Weaponized information asymmetry.

Listen to Aditya


And by the way, you should never be worried that an offer would be withdrawn if you politely negotiate.

I have seen this happen *extremely* rarely, mostly to women, and anyway is a giant red flag. It suggests you probably didn’t want to work there.

You wish there was no negotiating so it would all be more fair? I feel you, but it’s not happening.

Instead, negotiate hard, use your privilege, and then go and share numbers with your underrepresented and underpaid colleagues. […]