{"version":1,"type":"rich","provider_name":"Libsyn","provider_url":"https:\/\/www.libsyn.com","height":90,"width":600,"title":"From the archive: How should we think about IQ?","description":"Hello friends, and happy new year! We're gearing up for a new run of episodes starting later in January. In the meanwhile, enjoy this pick from our archives. ------ [originally aired October 16, 2024] IQ is, to say the least, a fraught concept. Psychologists have studied IQ\u2014or g for \u201cgeneral cognitive ability\u201d\u2014maybe more than any other psychological construct. And they\u2019ve learned some interesting things about it. That it's remarkably stable over the lifespan. That it really is general: people who ace one test of intellectual ability tend to ace others. And that IQs have risen markedly over the last century. At the same time, IQ seems to be met with increasing squeamishness, if not outright disdain, in many circles. It's often seen as crude, misguided, reductive\u2014maybe a whole lot worse. There's no question, after all, that IQ has been misused\u2014that it still gets misused\u2014for all kinds of racist, classist, colonialist purposes. As if this wasn't all thorny enough, the study of IQ is also intimately bound up with the study of genetics. It's right there in the roiling center of debates about how genes and environment make us who we are. So, yeah, what to make of all this? How should we be thinking about IQ? My guest today is Dr. Eric Turkheimer. Eric is Professor of Psychology at the University of Virginia. He has studied intelligence and many other complex human traits for decades, and he's a major figure in the field of \u201cbehavior genetics.\u201d Eric also has a new book out this fall\u2014which I highly recommend\u2014titled Understanding the Nature-Nurture Debate. In a field that has sometimes been accused of rampant optimism, Eric is\u2014as you'll hear\u2014a bit more measured. In this conversation, Eric and I focus on intelligence and its putatively genetic basis. We talk about why Eric doubts that we are anywhere close to an account of the biology of IQ. We discuss what makes intelligence such a formidable construct in psychology and why essentialist understandings of it are so intuitive. We talk about Francis Galton and the long shadow he\u2019s cast on the study of human behavior. We discuss the classic era of Twin Studies\u2014an era in which researchers started to derive quantitative estimates of the heritability of complex traits. We talk about how the main takeaway from that era was that genes are quite important indeed, and about how more recent genetic techniques suggest that takeaway may have been a bit simplistic. Along the way, Eric and I touch on spelling ability, child prodigies, the chemical composition of money, the shared quirks of twins reared apart, the Flynn Effect, the Reverse Flynn Effect, birth order, the genetics of height, the problem of missing heritability, whether we should still be using IQ scores, and the role of behavior genetics in the broader social sciences.  Alright folks, lots in here\u2014let's just get to it. On to my conversation with Dr. Eric Turkheimer. Enjoy!   A transcript of this episode is available here.   Notes and links 3:30 \u2013 The 1994 book The Bell Curve, by Richard Herrnstein a Charles Murray, dealt largely with the putative social implications of IQ research. It was extremely controversial and widely discussed. For an overview of the book and controversy, see the Wikipedia article here. 6:00 \u2013 For discussion of the \u201call parents are environmentalists\u2026\u201d quip, see here. 12:00 \u2013 The notion of \u201cmultiple intelligences\u201d was popularized by the psychologist Howard Gardner\u2014see here for an overview. See here for an attempt to test the claims of the \u201cmultiple intelligences\u201d framework using some of the methods of traditional IQ research. For work on EQ (or Emotional Intelligence) see here. 19:00 \u2013 Dr. Turkheimer has also laid out his spelling test analogy in a Substack post. 22:30 \u2013 Dr. Turkheimer\u2019s 1998 paper, \u201cHeritability and Biological Explanation.\u201d 24:30 \u2013 For an in-passing treatment of the processing efficiency idea, see p. 195 of Daniel Nettle\u2019s book Personality. See also Richard Haier\u2019s book, The Neuroscience of Intelligence. 26:00 \u2013 The original study on the relationship between pupil size and intelligence. A more recent study that fails to replicate those findings. 31:00 \u2013 For an argument that child prodigies constitute an argument for \u201cnature,\u201d see here. For a memorable narrative account of one child prodigy, see here. 32:00 \u2013 A meta-analysis of the Flynn effect. We have previously discussed the Flynn Effect in an episode with Michael Muthukrishna. 37:00 \u2013 James Flynn\u2019s book, What is Intelligence? On the reversal of the Flynn Effect, see here. 40:00 \u2013 The phrase \u201cnature-nurture\u201d originally comes from Shakespeare and was picked up by Francis Galton. In The Tempest, Prospero describes Caliban as \u201ca born devil on whose nature\/ Nurture can never stick.\u201d 41:00 \u2013 For a biography of Galton, see here. For an article-length account of Galton\u2019s role in the birth of eugenics, see here. 50:00 \u2013 For an account of R.A. Fisher\u2019s 1918 paper and its continuing influence, see here. 55:00 \u2013 See Dr. Turkheimer\u2019s paper on the \u201cnonshared environment\u201d\u2014E in the ACE model. 57:00 \u2013 A study coming out of the Minnesota Study of Twins reared apart. A New York Times article recounting some of the interesting anecdata in the Minnesota Study. 1:00:00 \u2013 See Dr. Turkheimer\u2019s 2000 paper on the \u201cthree laws of behavior genetics.\u201d Note that this is not, in fact, Dr. Turkheimer\u2019s most cited paper (though it is very well cited). 1:03:00 \u2013 For another view of the state of behavior genetics in the postgenomic era, see here. 1:11:00 \u2013 For Dr. Turkheimer\u2019s work on poverty, heritability, and IQ, see here. 1:13:00 \u2013 A recent large-scale analysis of birth order effects on personality. 1:16:00 \u2013 For Dr. Turkheimer\u2019s take on the missing heritability problem, see here and here.    1:19:00 \u2013 A recent study on the missing heritability problem in the case of height. 1:30:00 \u2013 On the dark side of IQ, see Chapter 9 of Dr. Turkheimer\u2019s book. See also Radiolab\u2019s series on g. 1:31:00 \u2013 See Dr. Turkheimer\u2019s Substack, The Gloomy Prospect.   Recommendations The Genetic Lottery, Kathryn Paige Harden Intelligence, Stuart Ritchie Intelligence and How to Get It, Richard Nisbett "Why our IQ levels are higher than our grandparents\u2019\u2019 (Ted talk), James Flynn   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com. For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social). ","author_name":"Many Minds","author_url":"https:\/\/disi.org\/manyminds\/","html":"