The guest
Richard Haier: Psychologist and neuroscientist, professor emeritus at UC Irvine, editor of the journal Intelligence, and author of 'The Neuroscience of Intelligence.' A pioneer in using brain imaging to study human intelligence.
What this episode covers
Haier explains the g factor (general intelligence) as the most replicated finding in psychology, how IQ tests estimate it, and why it appears stable, heritable, and resistant to training. The conversation tackles the design of IQ tests, the Flynn effect, and the validity of intelligence as a predictor of life outcomes from income to longevity. A large portion confronts the controversy around group differences in IQ, the Bell Curve, and Arthur Jensen's 1969 paper, with Haier arguing for following the data while communicating with compassion. It closes on the neurobiology of intelligence, consciousness research, AI, and the limits of what intelligence means for a meaningful human life.
Recommended on this episode
BookRecommendedISBN verified
The Bell Curve: Intelligence and Class Structure in American Life
Richard Herrnstein and Charles Murray
“you need to read it for yourself”
“but I would urge people who have heard about him and the bell curve and who think they know what's in it you are likely incorrect and you need to read it for yourself”— Richard Haier
The guest's own work
BookBy the guestISBN verified
The Neuroscience of Intelligence
Richard Haier
“first of all you have a great book on the neuroscience of intelligence you have a great course which is when i first learned you're a great teacher”— Lex Fridman
Also referenced (named, not recommended)
BookReferencedISBN verified
Human Diversity: The Biology of Gender, Race, and Class
Charles Murray
“one about human diversity where he goes through the data refuting the idea that race is only a social construct with no biological meaning”— Richard Haier
BookReferencedISBN verified
Facing Reality: Two Truths About Race in America
Charles Murray
“more recently he's written what might be his final say on this a book called facing reality where he talks about this again”— Richard Haier
BookReferencedISBN verified
Flowers for Algernon
Daniel Keyes
“have you read flowers of algernon yes that's to the question of intelligence and happiness there are many profound aspects of that story”— Richard Haier
MediaReferenced
Charly
Ralph Nelson
“it was a film that was very good if the film was called charlie you might be able to stream it on netflix or something”— Richard Haier
BookReferencedISBN verified
The Rise and Fall of the Third Reich
William L. Shirer
“one of the things i've recently re-read the rise and fall of the third reich which is i think the best telling of the rise and fall of hitler”— Lex Fridman
BookReferencedISBN verified
The Book of Five Rings
Miyamoto Musashi
“miyamoto musashi has this quote he's an ancient warrior famous for the book of five rings in the martial arts world”— Richard Haier
MediaReferenced
Clerks
Kevin Smith
“there's a movie called clerks you probably i've seen it yeah there's a funny scene in there”— Lex Fridman
Big reveals from this episode
- Haier claims the g factor is the most replicated finding in all of psychology, with no replication crisis.
- A Scotland study found people in the highest IQ quartile at age 11 were roughly twice as likely to still be alive 70 years later.
- The US military won't accept recruits with IQs under about 83 because they can't be trained for the jobs.
- Jensen's 1969 paper concluded compensatory education had failed and urged considering a genetic influence on group differences, making it the most infamous paper in psychology.
- Haier recounts telling Nightline that a genetic basis for IQ differences 'would be a good thing' because biological problems can be fixed, then refusing to say it on TV.
- The Coleman report and replications show school and teacher variables account for only about 10% of academic achievement.
- Haier's early PET studies found an inverse correlation between brain glucose metabolism and intelligence, leading to the brain efficiency hypothesis.
- Researchers increasingly attribute the Flynn effect to nutrition and health care, with evidence it is now slowing and possibly reversing.
Worth remembering
- Any random 12 mental tests will yield a g factor correlated above 0.9 with the g factor from any other random 12 tests.
- Reaction time on a complex light task correlates with the g factor, while simple reaction time barely does.
- The MMPI uses 'dust bowl empiricism' items whose content seems meaningless but empirically predicts personality disorders.
- About 16% of the US population, roughly 51 million people, have IQs under 85, including 14 million children.
- Adopted children's adult IQ scores correlate with their biological parents they never met, not their adoptive parents.
- IQ scores have drifted up about three points per decade, the Flynn effect, requiring tests to be periodically renormed.
- IQ correlates with cortical thickness and brain glucose metabolism, and identical twins reared apart have highly similar IQs.
- Twelve-year-olds in a Johns Hopkins study scored as high on the SAT math as incoming college freshmen, and 50 years later the top quartile of that top 1% had more patents and publications.
- AI researcher Francois Chollet built an IQ-style test for machines targeting tasks trivial for humans but hard for computers.
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