Today it’s a great honor to have Dr. Robert Plomin on the podcast. Dr. Plomin is Professor of Behavioural Genetics at the Institute of Psychiatry, Psychology, and Neuroscience at King’s College London. He previously held positions at the University of Colorado Boulder and Pennsylvania State University. He was elected a Fellow of the Academy of Medical Sciences and of the British Academy for his twin studies and his groundbreaking work in behavioral genetics. He is the author or coauthor of many books, including G is for Genes: The Impact of Genetics on Education and Achievement (with Kathryn Asbury), and most recently, BluePrint: How DNA Makes Us Who We Are.
In this wide-ranging conversation, we discuss the following topics:
- How Robert became interested in genetics
- The importance of going “with the grain” of your nature
- Robert’s twin studies methodology
- How genotypes become phenotypes
- How kids select their environments in ways that correlate with their genetic inclinations
- The genetic influence on television viewing
- How virtually everything is moderately heritable
- The effects of extreme trauma on the brain
- The developmental trajectory of heritability
- How the abnormal is normal
- How we could use polygenic information to inform educational interventions
- The potential for misuse of genetic information to select children for particular educational tracks
- Recent research on shared environmental influences on educational achievement
- The “nature of nurture”
- The variability of heritability across different cultures and levels of SES
- The role of education on intelligence
- How teachers can and cannot make a difference
- The genetics of social class mobility
- Free will and how we can change our destiny
Further Reading
Fifty years of twin studies: A meta-analysis of the heritability of human traits
The nature of nurture: effects of parental genotypes
Variation in the heritability of educational attainment: An international meta-analysis
Genetic analysis of social-class mobility in five longitudinal studies
Large cross-national differences in gene x socioeconomic status interaction on intelligence
How much does education improve intelligence? A meta-analysis
Are cognitive g and academic gone and the same g?
A systematic review of personality trait change through intervention
How scientists are learning to predict your future with your genes
Using nature to understand nurture
Can ‘genius’ be detected in infancy?
A brief history of everyone who ever lived
this was a great discussion! it would be great to have more like it.
Epigenetics – a term I’ve heard in other podcasts describing how one can turn on and off genes for physical health benefits. Just wondering whether behavioural geneticists use the term in psychology? Whether genes that would encourage risk taking could be turned off for example in addiction management via behavioral interventions?
Good conversation, thanks. What I find particularly interesting about Plomin’s viewpoint is that he combines a belief in the strong impact of genetic causation with a belief that outcomes can nevertheless be improved (by using the genetic information). The example of predicting reading difficulties illustrates that point well, provided that early detection really does allow interventions to work better.
Regarding the disagreement on the value of meta-analyses, this paper by the usual suspects recently appeared on my radar: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3271372
From the abstract:
“For example, p-hacking that only slightly increases the false-positive rate of individual studies, from 5% to 8%, increases the false-positive rate of a 5-study internal meta-analysis to 45%, and a 10-study internal meta-analysis to 82%. […] We recommend to never draw inferences about the existence of an effect from an internal meta-analysis.”
Alternative presentation: http://datacolada.org/73
Thank you for this honest conversation.
On the flipside, that turns me away even more from reading any papers in psychological “science”. I’m aware of the replication crisis, but listening to R. Plomin taking down these meta-analysis from top tier intelligence and behavioral genetics researchers just puts the last nail in the coffin.
A follow up would be great. Maybe you could talk exactly about these topics, e.g., why most of the publications in social sciences are useless and just a waste of taxpayers’ money and how we could stop this (and if such projects like Open Science can make a change). I guess Prof. Plomin has something to say about that — he already had few strong words about that in some previous interviews. I don’t think by the way that “open universities” that he advocates would help this particular problem (education maybe, but not research).
I was wondering why you, (Dr. Kaufman) were so upset with the idea of testing children for intelligence, when your own case of being considered ‘unintelligent’ because of anxiety might have been overturned with DNA testing that showed your actual intelligence (which I am certain would have been the case). Just confused me because it seems like the perfect solution to these sorts of problems that children have in school that are related more to temperament than learning.
Love your podcast,
a psychology hobbyist.
I would LOVE a follow-up and more. I think the conversation went in several directions. It would be interesting to hear you 2 unpack some of the bigger concepts (e.g., cultural issues, twin stuff).
Dr. Plomin’s explanation of variance and means practical but so important for drawing conclusions of whether they make a difference.
Interesting podcast — it got my blood pressure rising too :). I can’t believe that throughout this entire discussion epigenetics was never mentioned! I agree with Dr. Kaufman with respect to the significant role of environment dictating how our DNA ultimately manifests itself in different individuals. Emerging evidence points to the important role of environmental-induced epigenetic changes that determine how our genes are expressed and thus what behavioral (and beyond) phenotypes individuals develop throughout their lives. For example, check out this review by Alam, Abdolmaleky and Zhou from the American Journal of Medical Genetics: Microbiome, inflammation, epigenetic alterations, and mental diseases.
As such, simplistic DNA sequencing of babies at birth is most definitely not deterministic in my opinion.