Episode 11: The Trouble With Twin Studies - Does DNA Really Make Us Who We Are? (with Jay Joseph)

In this episode, I sit down with clinical psychologist Dr. Jay Joseph to discuss the issue of genetic research in IQ, personality, and psychiatric disorders—particularly in the context of the thirtieth anniversary of the publication of "The Bell Curve." While twin studies are exalted by behavioral geneticists as the gold standard research that definitively settles the so-called nature-nurture debate, our conversation explores a variety of problems with such claims. Dr. Joseph offers a strong critique of twin study methodologies and assumptions, and urges a very serious and thoughtful reconsideration of many of the field’s findings in light of psychology’s replication crisis. We discuss the so-called “missing heritability problem” posed by more modern methods of evaluating the genetic influence on IQ and personality, the relationship between ongoing genetic research and big pharma, and why he believes the findings of “The Bell Curve” fail to hold up under scrutiny thirty years later.

Jay Joseph, Psy.D. is a clinical psychologist practicing in the San Francisco Bay Area. He has written critically about genetic research in the social and behavioral sciences continuously since the late 1990s, and is critical of medical models of human psychological distress and dysfunction. He is the author of four books, most recently Schizophrenia and Genetics: The End of an Illusion (2023). A complete list of his books, book chapters, and peer-reviewed articles can be found on his website: www.jayjoseph.net. Many of his online articles can be found on the Mad in America website: www.madinamerica.com

The Bell Curve at 30: A Closer Look at the Within- and Between-Group IQ Genetic Evidence: https://osf.io/preprints/psyarxiv/jz7ku .css-j9qmi7{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;font-weight:700;margin-bottom:1rem;margin-top:2.8rem;width:100%;-webkit-box-pack:start;-ms-flex-pack:start;-webkit-justify-content:start;justify-content:start;padding-left:5rem;}@media only screen and (max-width: 599px){.css-j9qmi7{padding-left:0;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;}}.css-j9qmi7 svg{fill:#27292D;}.css-j9qmi7 .eagfbvw0{-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;color:#27292D;}