In today's episode, I spoke with Prof. Robert Plomin, a leading expert in psychology and behavioral genetics, and the author of "Blueprint: How DNA Makes Us Who We Are." Through his research and best-selling book, Robert has made a strong case for the 'nature' side of the Nature vs. Nurture debate. We spoke at length about the significant role genetics play in shaping our personalities, behaviors, and preferences. It might be more than you think!
We kick off the episode exploring the misunderstood concept of heritability. Robert clarifies that heritability does not equal inevitability, shedding light on how genetic research focuses on 'what is', not 'what could be'. As we discussed the vast history of adoption and twin studies, we explored the roles that our genes and our environment have in shaping who we are. For example, adoption studies have consistently shown that adopted children had more in common with their biological parents than their adopted parents, suggesting that genes play a stronger role than the environment in shaping a child's personality and behavioral tendencies.
Robert shed light on the distinction between shared vs. non-shared environments and how individuals with distinct temperaments can shape their surroundings in quite unique ways. Even within the same family, siblings can elicit vastly different responses from their parents due to the differences in their genes and personality.
We then dove into the world of personality, speaking about how genes show up in early temperament dimensions, such as a child's tendency to 'approach' or 'avoid', as well as in more developed traits such as extraversion and neuroticism.
Robert and I spoke about the research on IQ and genetics, noting the heritability and correlation of general intelligence 'g', school achievement, and other cognitive abilities. He explained the concept of 'generalist genes' and while single-gene disorders do exist - more often than not: (1) a single gene influences many traits & (2) a single trait is influenced by many genes. With that in mind, we spoke about how psychopathologies are essentially extreme ends of normal personality traits, rather than there being a 'distinct gene for schizophrenia.' OCD can be thought of as an extreme manifestation of conscientiousness, orderliness, and a need for familiarity and ritual, for instance. And schizophrenia can be thought of as an extreme manifestation of trait openness, creativity, and divergent thinking.
For parents tuning in, we spoke at length about how this research can influence the way we parent. Robert emphasizes the importance of facilitating a child's natural development rather than molding them in a specific direction. Much of our child's personality, behaviors, and preferences are determined by their genetics. The best we can do is help them explore their innate interests and to develop their natural strengths as much as they can through practice and experience.
We finished off with DNA genotyping, polygenic scores, and services like 23andMe, Ancestry.com, and Stratagene to find out more about your own genetics.
Tune in to gain a deeper understanding of how your genetic blueprint shapes who you are. If you're curious about personality, intelligence, and the broader implications of genetic science, this episode is a must-listen. Enjoy the journey into the fascinating world of behavioral genetics with Prof. Robert Plomin.
For more insights from Prof. Plomin, check out his work, and don't forget to subscribe for future episodes!
🔗 Blueprint: How DNA Makes Us Who We Are - www.amazon.com/Blueprint-How-...
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00:00 Genetics 101: What Does Heritability Actually Mean?
9:54 Twin & Adoption Studies
17:13 Genetics Matter More As We Age
19:03 Genetics Play a Big Role in IQ & Cognitive Abilities
22:10 The Race to University: We're Putting Too Much Pressure on Kids
23:47 A Message to Parents: Genes Greatly Influence Your Child's Personality!
31:46 Twin Studies & Shared vs. Non-Shared Environments
39:00 The Nature of Nurture: Our Genes Also Shape Our Environment
44:23 Provocative Observations: Bad Behavior Runs in a Family because of Genes
46:45 Novelty Seeking & Extraversion: Traits Linked with Cheating & Divorce
47:39 Personality & Genes
1:01:06 Psychopathologies are Extreme Ends of Normal Personality Traits
1:14:15 DNA Revolution: 23andMe, Ancestry.com, Stratagene, SNPs, & Polygenic Scores