The Nature & Nurture Podcast

Dr. Cory Clark is a social psychologist and Director of the Adversarial Collaboration Project at the University of Pennsylvania. 

In this episode we talk about adversarial collaboration and open science, meta-psychology research on common biases in psychology carried by psychologists themselves, and its moralization. We also discuss gender differences in moral beliefs, how social media and culture shape moral norms, how rationality can combat this, and whether faith is compatible with rationality.

Dr. James Roney is a Professor of Psychological & Brain Sciences at the University of California, Santa Barbara, where he runs the Human Behavioral Endocrinology Lab. In this episode we talk about the proximate and ultimate evolutionary explanations of different sex hormones’ roles in coordinating motivated behavior, such as testosterone’s influence on aggression and sex drive, and ovarian hormones’ influence on sex and food drive. We discuss how testosterone leads to sex differentiation in the brain and body both prenatally and during puberty; threshold effects, rather than continuous relationships, between testosterone and motivation; the opposite effects of estradiol and progesterone on women’s sex and food motivation across the menstrual cycle. We also discuss genetic differences in the receptors to different hormones, their interactions with other hormones, and how these subtle differences may predict traits ranging from morphology to sexuality. Lastly, we discuss Jim’s recent research using daily diaries and saliva hormones to test whether daily hormonal fluctuations influence sex drive and other motivated behavior, how smell and pheromones influence attraction in males and females, and how sex hormones influence reward processing in the brain, particularly during puberty. Timestamps: 0:00:51 Hormones act as coordinators in the body 0:02:06 Example of testosterone's input and output relationships 0:05:41 Importance of understanding the inputs and outputs of hormones 0:07:43 Conservation of hormone functions from non-human species to humans 0:09:35 The role of hormones in motivated behaviors 0:11:19 Time lag between stimulus event and hormone response 0:15:19 Evolutionary theories and mating behavior tied to sex hormones 0:18:23 Evolution and psychological functions of testosterone and oxytocin 0:20:08 Understanding hormone inputs and context for coordinated effects 0:21:58 Oxytocin paradox and effects on maternal aggression 0:23:33 Confounding effects of multiple signals on hormone outputs 0:25:14 Individual variability and receptor sensitivity to testosterone 0:26:47 Genetic polymorphism and developmental calibrators of individual differences 0:28:10 Prenatal testosterone and sexual orientation 0:38:21 Threshold effects of testosterone 0:41:06 Continuous relationship between estradiol, progesterone, sex drive, and food drive in women 0:53:01 Testosterone's effect on reward may be more generalized than estradiol and progesterone 0:54:47 Estradiol may affect satiety mechanisms, not just reward systems. 0:56:56 Theoretical framework for risk taking and impulsivity. 0:58:26 Research on anxiety and depression in females during puberty. 0:59:58 Effects of testosterone on motivation and individual differences 1:08:08 Study on concealed ovulatory timing, pheromones, and scent attractiveness during ovulation

Dr. Joseph Henrich is an anthropologist and Chair of the Human Evolutionary Biology Department at Harvard University, where he runs the Culture, Cognition, and Coevolution Lab. Joe is also the author of the WEIRDest People in the World and The Secret of Our Success.

Timestamps:0:00:46 Environmental factors leading to cultural evolution0:03:19 Cultural adaptations, rituals, and technological advancements0:05:11 Cultural adaptations operating outside of conscious awareness0:07:04 The role of religion in cultural transformations0:09:40 Impact of religious prohibitions on social ties0:10:59 Exploring the spread of monotheistic religions0:12:01 The expansion of gods and competition among groups0:13:55 Transition to monotheism and personification of social awareness0:16:18 Intergroup competition and tension between small and large group cooperation0:17:37 Individualistic guilt vs collectivist shame0:19:18 Variation in use of mental state terms in folktales0:23:00 Patterns in cooperation and moral judgment from human nature and cultural evolution0:24:44 Cultural evolution and species differences0:25:56 Intersection of biology and culture in sex and gender differences0:26:24 Culture changes our biology and brain0:28:28 Male inclination towards violence observed in every human society0:29:50 Testosterone levels and aggression linked to social hierarchy0:30:28 Gender paradox: greater gender equality, bigger personality/morality differences0:32:06 Sex differences observed in primates0:35:15 Fathering dynamics in human societies0:37:26 Genetic fitness and hunter-gatherer societies0:41:28 Sex ratio, crime rates, and marriage markets[0:43:32 Dating apps, competition, and inequality0:46:14 Zero sum games, land, and cultural differences0:53:18 Demographic changes and the impact on parenting styles.0:55:07 Adversity-exposed brain and its relation to life history theory.0:57:37 Using surname diversity as a proxy for diversity of thought and experience in a society.1:01:50 Linking surname diversity to occupational diversity, trust, and innovation1:04:32 Christianity's impact on scientific revolution and analytic thinking1:06:11 Bias towards progress and the concept of progress emerging

Dr. Massimo Pigliucci is a philosopher and evolutionary biologist, the K.D. Irani Professor of Philosophy at the City College of New York, a fellow of the American Association for the Advancement of Science, a prolific author of over 100 academic papers, 16 books including Evolution: The Extended Synthesis, and the best-selling How to Be a Stoic, as well as thousands of posts and short clips of wisdom on his Stoic Meditations and Practical Wisdom podcasts and Rationally Speaking blog. His research interests include the philosophy of science and evolutionary biology, the nature of psueoscience, and practical philosophies like Stoicism and Neoskepticism.

Dr. Stephanie Bugden is an Assistant Professor of Psychology at the University of Winnipeg, and an expert in the psychology and neuroscience of children's math learning. In this episode we discuss the nature versus nurture debate in math ability and the genetic and environmental influences on math learning. Dr. Bugden explains that both genetics and early learning experiences play a role in individual differences in math ability, verbal IQ, and visuospatial IQ. We also discuss whether there are sex differences in math ability at various ages, and how these differences might be confounded by math anxiety. Dr. Bugden also shares her research on the neurobiological processes involved in math learning and the challenges of studying dyscalculia, a math learning disability analogous to dyslexia. Lastly, we discuss the impact of COVID-19 on math learning and the potential exacerbation of socioeconomic inequalities in education.

Dr. Jonas Kaplan is a cognitive neuroscientist and faculty at USC's Brain and Creativity Institute, where he co-directs the the Dornsife Cognitive Neuroimaging Center. His research focuses on consciousness, the self, belief, empathy, social relationships, action perception and creativity. In this reunion episode, episode, we discuss active inference and predictive processing theories of consciousness, panpsychism, philosophy of mind, and the difference between interoception and exteroception. We further consider the evolutionary psychology of self-awareness, empathy, status seeking, and sexuality, and how these translate to modern technology and mental health. Lastly, we discuss neuroscience and its connection to film and literature, which Jonas discusses on his new podcast Float, and how this connects to cross-cultural analyses of religion, archetypes, and recent debates between Sam Harris and Jordan Peterson on the psychology and utility of religion. Timestamps: 0:01:30 Active inference and predictive processing 0:04:24 Skepticism about applying active inference to interoception 0:08:33 Consciousness, affect, and emotion 0:11:40 Dualism in neuroscience and philosophy of mind 0:13:41 The role of the body in consciousness and empathy 0:16:33 The limitations and challenges of artificial intelligence and empathy 0:20:09 The relationship between consciousness, narrative, and selfhood 0:26:23 Panpsychism and self-organizing systems 0:30:40 Postmodernism and categorical distinction 0:34:04 Pragmatism in statistics and narrative 0:38:08 How the brain recognizes narrative structure 0:40:32 Storytelling in hunter gatherers 0:42:04 Sexual selection, dominance, and creativity 0:49:24 The self as a collection of sub-personalities 0:52:43 Social comparison, stress, and mental health 0:55:08 Sexual selection, social status, and the crowdsourcing of wisdom 1:02:31 The psychology of dating apps 1:07:24 The potential impact of different app designs on mental health 1:09:32 The immersive experience of storytelling and audience engagement 1:13:34 The intersection of neuroscience, film, and storytelling 1:17:03 Black Mirror, technology, and memory 1:20:00 The value of forgetting and the nostalgia bias in memory 1:21:49 The cultural evolution of religion 1:25:24 Archetypes and their usefulness 1:30:40 Pantheism and mathematical Platonism 1:35:24 The necessity of axioms in science

Dr. Paul Bloom is a Professor of Psychology at the University of Toronto, and the Brooks and Suzanne Ragen Professor Emeritus of Psychology at Yale University. Paul studies how children and adults make sense of the world, with special focus on language, pleasure, morality, religion, fiction, and art. He is the author of seven books, including his latest Psych: The Story of the Human Mind. In this episode, we sample some of the many, many topics covered in Psych, including Freud, evolutionary psychology, language development, moral development, and social cognition. We also talk about Paul’s early research on language development and moral cognition, my own research on pubertal hormones and brain development, and the meta-psychology of what makes podcasts interesting. 0:00:02 Introduction to Dr. Paul Bloom and his research 0:01:10 The story behind the article "Natural Language and Natural Selection" 0:05:20 The connection between developmental psychology and evolutionary psychology 0:08:20 The concept of ontogeny recapitulating phylogeny 0:11:41 Transition from language development to moral development 0:13:42 The relationship between disgust and morality 0:16:18 The parallels between physical traits and moral traits 0:19:23 The connection between free will and moral responsibility 0:25:04 The nature-nurture debate and the role of genetics in psychology 0:31:06 The continuum of traits and the question of determinism 0:34:07 The influence of Freud and the shift towards empirical psychology 0:45:06 The history of psychology and the influence of old theories 0:55:20 The role of clinical psychology and the question of mental illness1:01:21 The psychological tendency to rationalize silver linings and find upsides in negative traits 1:06:17 Paul's role as an editor for a journal and prioritizing what to read in psychology 1:08:02 The social intimacy and connection of podcasts

Dr. Ben Smith is a neuroscientist and postdoctoral research fellow in the Social Affective Neuroscience Lab at the University of Oregon.

In this episode we talk about Ben’s research on the social neuroscience of risky decision-making, computational modeling of the reward and punishment system during decision-making, the abstract-concrete tangibility axis of the prefrontal cortex, moral and ideological decision-making, and how decision neuroscience connects to habits, health, and effective altruism.

Dr. Emily Jacobs is an Associate Professor of Psychological & Brain Sciences at the University of California, Santa Barbara, where she studies how sex hormones impact brain structure, function, and cognition, particularly during menopause and across the menstrual cycle. 

In this episode we talk about how the brain is an endocrine organ: one which communicates through hormones. We talk about Emily’s research on brain aging and cognition, how sex hormones change the brain during menopause and across the menstrual cycle, and how sex hormones lead to sex differentiation in the brain. We also talk about Emily’s research for women’s health, historical barriers slowing advancement in our understanding of the female reproductive cycle across the lifespan, and modern research efforts taken to remedy this.

Dr. Judith Fan is an Assistant Professor of Psychology at Stanford University, where she runs the Cognitive Tools Lab: https://cogtoolslab.github.io/
In this episode, Dr. Fan discusses the concept of reverse engineering the human cognitive toolkit, which involves uncovering the principles and constraints that shape our thinking and the tools we use to support our cognitive processes. She explains that cognitive tools are material artifacts, such as numbers, pictures, and language, that help us think and communicate. Dr. Fan highlights the importance of understanding the mechanisms behind these tools and how they interact with our brains.She explores the use of pictures as a cognitive tool and how they have been used throughout history to encode and communicate knowledge. Dr. Fan also discusses the convergence between artificial neural networks and the human brain in understanding visual inputs, such as faces. She explains that these systems can approximate the behaviors of real neurons and provide insights into how our brains process visual information.Dr. Fan emphasizes the role of education in shaping our cognitive toolkit and the importance of providing learners with multiple modalities for engaging with information. She also discusses the potential of emerging technologies, such as artificial intelligence and machine learning, in supporting rich and generative forms of learning. 0:00:02 Introduction to Dr. Judy Fan and her research 0:00:30 Definition of reverse engineering and cognitive toolkit 0:02:06 Examples of cognitive tools like accounting devices and pictures 0:08:50 Connection between cognitive tools and advancements in computer vision 0:17:51 Discussion on the similarities between artificial neural networks and human brain 0:22:04 The use of AI systems like DALL·E to create images 0:25:26 The influence of historical and cultural context on cognitive toolkits 0:27:21 The role of education in shaping cognitive toolkits 0:32:15 The potential genetic component of cognitive toolkits 0:37:15 The debate on visual learners and individual differences in learning 0:40:24 The interaction between cognitive tools and unlocking new abilities 0:44:20 Dr. Judy Fan's excitement about future research at Stanford 0:47:14 The potential of screens and technology in education 0:49:41 The importance of scaffolding activities and avoiding drawbacks 0:52:51 The significance of statistics and data science education 0:56:16 The need for more people to think in shades of gray

Dr. Roy Baumeister is a renowned social psychologist and Professor of Psychology at the University of Queensland. In this episode we explore a variety of topics about Roy's research on self-control and decision-making, human sexuality, and the need for social belongingness.

Dr. Colin DeYoung is a personality neuroscientist and Professor of Psychology at the University of Minnesota, where he directs the DeYoung Personality Lab. 

In this episode we talk about the science of personality, including the Big Five (Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism) and their neural correlates. We discuss how personality is measured, genetic and environmental influences on personality and its development over time, and the Big Five traits’ connections to areas of my own research on the neuroendocrinology of reward sensitivity and inhibitory control.  

Dr. Barry Giesbrecht is a Professor of Psychological & Brain Sciences at the University of California, Santa Barbara, where he directs the Attention Lab. https://attentionlab.psych.ucsb.edu/

Dr. Mahzarin Banaji is the Richard Clarke Cabot Professor of Social Ethics in the Department of Psychology at Harvard University and co-author of the New York Times Bestseller Blindspot: Hidden Biases of Good People. She is the recipient of countless awards including being one of APA’s William James Fellows for outstanding contributions to psychology and a member of the National Academy of Sciences. 

In this episode we talk about Mahzarin’s career in cognitive and social psychology, and the development of the Implicit Association Test (IAT). We discuss myths and facts about implicit bias, including how the brain forms automatic implicit associations based on statistical learning, and how these biases can be formed entirely independently of conscious prejudice. We discuss examples of this research ranging from moral psychology, to racial bias, and how IAT results differ cross-culturally. Lastly, we discuss Mahzarin’s ongoing research combining natural language processing research and geospatial data to estimate how regional IAT scores correlate with different biases expressed on social media posts coming from different areas. 

Dr. John Delony is a mental health and wellness expert with over two decades of experience working as a researcher, educator, and crisis responder. He is the host of the wildly successful, and live-changing advice-giving Dr. John Delony show, and bestselling author of Own Your Past, Change Your Future: A Not-So-Complicated Approach to Relationships, Mental Health, and Wellness. In this episode, John and I have a wide-ranging conversation centered around the neuropsychology research and personal anecdotes covered in Own Your Past, Change Your Future. We discuss big questions concerning nature and nurture, free will and determinism, child development and parenting, puberty and hormones, finding a balance between motivation and perfectionism, and the neuropsychology of anxiety, and hear a sneak preview of John’s next book.

Dr. Leah Somerville is the Grafstein Family Professor of Psychology at Harvard University, and my very own PhD advisor! She runs the Affective Neuroscience & Development Laboratory, where we study how brain and pubertal development shapes motivation, cognition, emotion, and behavior during adolescence. In this special 100th episode, I interview Leah in person about her research background, the importance of adolescence as a sensitive period for brain development, myths and facts about puberty, hormones, sex differences, and teenage risk-taking, and where developmental neuroscience fits into juvenile justice and our legal conceptions of rational agency.

Dr. Karl Friston is a Professor of Neurology at University College London and one of the world's most influential neuroscientists. He invented statistical parametric mapping, voxel-based morphometry, and dynamic causal modeling, and has authored or co-authored hundreds of scientific publications detailing out these theoretical and methodological advancements in neuroscience, and is also the mind behind the theory of Active Inference: The Free Energy Principle in Mind, Brain, and Behavior. The brain is a fantastic organ, not only because it is amazingly complex, but because it is constantly generating fantasies. In this episode we talk about active inference, what Dr. Friston has called “the physics of belief,” which states that the brain is fundamentally predictive. We discuss the theory of active inference and the mathematics behind the free energy principle, which states that the brain aims to minimize “free energy” or entropy by optimizing to minimize prediction error and maximize expected information gain. We discuss how active inference is inherently tied to motivation, and that consciousness, emotion, and strategic decision making can all be framed in terms of monitoring and minimizing prediction error. We also compare and contrast active inference with other theories of consciousness such as integrated information theory. Lastly, we discuss the neurobiology of active inference and its parallels to cybernetic intelligence, such as how activational and organizational effects of hormones on brain development are analogous to manipulating numeric inputs or weights in an artificial neural network.

Dr. Lixing Sun is a Distinguished Professor of Biology at Central Washington University, and author of The Liars of Nature and the Nature of Liars: Cheating and Deception in the Living World. In this episode we talk about the evolution of lying and deception as distinct strategies. Lying organisms actively alter truth by displaying false signals, whereas deception occurs by exploiting cognitive biases to trick others. We talk about lying and deception in a wide range of species, from insects, to fish, to reptiles, to primates, and finally, humans. We discuss the role of deception in sexual selection, evolutionary arms races between innovative methods to cheat and counter-cheating strategies, such as costly signaling and the evolution of human social intelligence, and how large-scale institutions and social media are both particularly threatening and promising to prosociality in humans.

Dr. Mark Moffett is an ecologist and author of several books including Adventures Among Ants and The Human Swarm. 

In this episode we talk about social behavior in species ranging from ants, to lizards, to chimpanzees, to humans, and their similarities and differences. We talk about intelligence as typically individually-defined, as well as distributed “hive mind” intelligence in simple species like ants, where each ant can function like a neuron in a whole-brain network. We also discuss the evolution of human sociality and compare our propensity for peace and aggression to chimpanzees and bonobos, and our unique social intelligence. Lastly, we talk about cultural evolution and cross-cultural diversity in human societies, and how we both learn and can transcend group biases.

Dr. Ovul Sezer is a behavioral scientist, Assistant Professor of Management and Organizations at Cornell University, and stand-up comedian. 

In this episode we talk about the psychology of comedy and Ovul’s research on impression (mis)management. We discuss effective and ineffective forms of communication, balancing confidence and humility, and the importance of first impressions in social and professional relationships. We also talk about the psychology of virtue signaling, humble bragging, and navigating impression management in the modern social media age.

Dr. Edouard Machery is a Distinguished Professor at the University of Pittsburgh and Director of the Center for Philosophy of Science. He's published over 150 articles and book chapters on a diverse range of topics including the philosophy of cognitive science, moral psychology, the utility of evolutionary theory and neuroscience for understanding cognition, folk psychology, and experimental philosophy. 

In this wide-ranging episode we talk about Edouard’s research on cross-cultural differences in conceptions of free will and determinism, free will and moral responsibility, and how we define a rational agent. We also talk about neuropsychological research on value and decision making, the free energy principle as a theory of cognition, and how statistical reasoning requires us to create probabilistic cutoffs for action, both in science and in decision making. Lastly, we talk about the development of cognition and emotion both within human lifespans and across our evolutionary phylogenetic tree. 

Dr. Scott Grafton is a Distinguished Professor of Psychological & Brain Sciences at the University of California, Santa Barbara. He directs the Action Lab, which focuses on the neuroscience of goal-directed movement. 

In this episode we discuss Dr. Grafton’s background in neurology research, and the historical progression of integrating the neuroscience of movement, perception, and goal-setting. We talk about how modern neuroimaging techniques replicated and expanded upon findings from early neuropsychological studies of brain damage, and how Dr. Grafton uses dense-sampling techniques to scan individual’s brains repeatedly over short intervals, to study how learning changes the structural and functional organization of brain regions involved in perception and motor control. Lastly, we talk about Dr. Grafton’s ongoing research of how the brain interacts with the rest of the body during physical activity to maintain allostasis, and the implications this has for our understanding of the links between perception, action, and brain health. 

Dr. Dan Conroy-Beam is an Associate Professor of Psychology at the University of California, Santa Barbara. Dan uses an evolutionary and computational perspective to understand mate choice and mating relationships. Specifically, he is interested in how mate preferences are integrated with one another computationally in order to make mating decisions as well as the decision rules people use to navigate their mating markets and their relationships. Dan's work combines agent-based modeling of mate choice with studies of real couples to compare and explore candidate models for how people evaluate potential mates, pursue partners, and regulate their relationships. Learn more about Dan's work at: https://www.danconroybeam.com/

In this episode we cover a wide range of topics including Dan's research on computational mate choice, the theory and history of sexual selection, different reproductive strategies and status signaling in humans and other animals, and environmental factors influencing mate choice ranging from sex ratio, to resource availability, to modern dating app environments. 

Dr. Rob Henderson is a psychologist best known for his research on luxury beliefs. 

In this episode, we talk about risk and resilience factors for success in America, including growing up in stable two-parent households. Rob shares how his experience growing up in the foster care system and his military service primed him for identifying luxury beliefs of the upper class during his studies at Yale and Cambridge. We discuss how luxury beliefs confer status upon elites, but disproportionately harm people in poor and working-class communities. As a case-study, we talk about changing norms surrounding monogamy and casual sex. Lastly, we talk about evolutionary pressures for and against monogamy, cooperation, and different moral values.

0:00:02Introduction to Dr. Rob Henderson and his research on luxury beliefs and social status0:00:47Discussion on the deteriorating state of young men in America0:03:21The differential effects of family structure on boys and girls0:04:56The interaction between nature and nurture in determining life outcomes0:06:08The impact of environmental inputs on cognitive ability and personality0:08:38The importance of stable and decent childhoods for children's well-being0:11:54The different ways in which "Lost Boys" manifest their struggles0:14:35The role of the military in providing structure and stability0:16:26The cultural shock experienced by Dr. Henderson at Yale0:20:22The concept of luxury beliefs and their role in conferring status0:25:21The moralization of luxury beliefs and the language treadmill0:28:08The harms caused by luxury beliefs, particularly in relation to monogamy0:36:56The impact of luxury beliefs on lower status people0:45:40The impact of luxury beliefs on mating psychology and relationships0:53:49The consequences of polyamory and the importance of monogamy for children1:00:08The potential consequences of a society-wide shift towards polyamory1:05:04The frustration of entitled attitudes towards income and education1:05:40The complexity of evolutionary forces and moral norms1:06:41The limitations of grounding morality solely in evolutionary models1:08:11The influence of economic education on selfish behavior in games1:09:21The importance of reputation and belonging in human psychology1:11:30Dr. Henderson's book and its exploration of personal experiences and social commentary

Dr. C. Sue Carter is a Professor of Psychology at the University of Virginia and Distinguished Research Scientist at Indiana University, where she also holds an Emerita position as Rudy Professor of Biology and was formerly Director of the Kinsey Institute for Research in Sex, Gender, and Reproduction. She is a Fellow and past President of the International Behavioral Neuroscience Society, and is known for her pioneering work on oxytocin, the love hormone, and its role in parental care and romantic pairbonding.  

In this episode we discuss how neuroendocrinology research has evolved over the course of Dr. Carter’s career, and how oxytocin became known as “the love hormone”. We discuss her early research examining oxytocin’s role in parental care, pairbonding, and sex drive in prairie voles, and contrast these findings to early evolutionary theories centered around testosterone and other sex hormones. We also talk about vasopressin, a hormone related to oxytocin, and discuss its role in more nuanced forms of care such as defensive aggression. Dr. Carter introduces the term of “sociostasis” as a social form of homeostasis which oxytocin and vasopressin are central to regulating. Lastly, we talk about oxytocin’s interactions with sex and stress hormones prenatally, during infancy, and during puberty, and how the early environment may epigenetically our oxytocin receptors and have lifelong impacts.

Dr. Adam Morris is a cognitive scientist and Postdoctoral Research Fellow in Psychology at Princeton University.

In this episode we talk about Adam’s research on the connections between mindfulness, decision-making, and introspection. We talk about the cognitive mechanisms involved involving in weighing pros and cons of your decisions, how various decision-making strategies may be computationally modeled, and how there may be a disconnect between people’s interoceptive beliefs about their decision-making processes, and what they actually do. Lastly, we talk about the science of mindfulness, and Adam’s ongoing research plans of an intervention study to test whether mindfulness training helps people introspect better about their own decision-making.

Dr. Brynn Sherman is a cognitive neuroscientist and postdoctoral research fellow at the University of Pennsylvania.

In this episode we talk about Brynn’s research on the interaction between statistical learning and memory errors, and how memory is studied using behavioral tasks and neuroimaging. We discuss the distinction between episodic memory and semantic memory, memory encoding and consolidation, and between knowing and remembering. We also discuss Brynn’s more recent research on the effects of stress and sleep on memory, and how these effects manifest in the brain.

Dr. Michael Levin is a developmental and synthetic biologist at Tufts University, where he is the Vannevar Bush Distinguished Professor and director of the Allen Discovery Center and Tufts Center for Regenerative and Developmental Biology.

In this episode we talk about Mike’s research, which ranges from studying the molecular biology of cancer, to the bioelectrics of limb regeneration, to memory and higher-order cognition. Mike describes the overall theme of his research as understanding the embodied nature of cognition in organic and synthetic systems, and the philosophical implications of this worldview. We discuss a wide variety of topics ranging from the neurobiology of planarian flatworms, to the future of regenerative medicine, to philosophical questions about the definitions of life, consciousness, and artificial intelligence.

0:02:05Exploring the concept of mind embodied in different architectures0:03:26Understanding morphogenesis as a collective intelligence of cells0:04:47Shift in problem space and intelligence from single cells to multicellular structures0:06:42The intentionality of animals and the continuum of agency0:09:27Choosing the appropriate model system for research0:11:11Dr. Levin's background and evolution of his research0:17:10Interest in the intersection of engineering and biology0:19:59Studying the bioelectric communication in cellular networks0:22:56Computational models of morphogenesis and cognitive aspects of development0:25:19The complexity of intelligence and the binary distinction of living0:27:25The continuum of life and the challenges of defining it0:29:49The ability to learn and memory in planaria0:37:00The challenges of defining individual identity and memory0:39:23The unique regenerative abilities of planaria and salamanders0:41:06The future of regenerative medicine and synthetic biology0:45:24The potential of somatic psychiatry and tissue training regimes0:47:44Understanding complex cognitive machines and the limits of understanding0:51:06Different notions of understanding emergent phenomena0:53:29The challenges of understanding neural networks and biological networks

Dr. Daniel Schacter is a Professor of Psychology at Harvard University where he runs the Schacter Memory Lab, and author of The Seven Sins of Memory.

In this episode we talk about the history of memory research over the last 100+ years, beginning with simple behavioral tasks and up to modern neuroimaging. Dr. Schacter overviews different dimensions of memory scientists have identified, including episodic vs. semantic, implicit vs. explicit, and the processes of encoding, consolidation, retrieval, and reconsolidation. We then discuss each of The Seven Sins of Memory: Transience, Absent-Mindedness, Blocking, Misattribution, Suggestibility, Bias, and Persistence. Lastly, Dr. Schacter describes some of his more recent research on the relationship between episodic memory and imagination and creativity.

Dr. Dorsa Amir is a psychologist, anthropologist, and postdoctoral research fellow at the University of California, Berkeley.

In this episode we talk about child development and decision-making through the interdisciplinary lenses of anthropology, psychology, evolutionary biology, and behavioral economics. We talk about some of Dorsa’s theoretical research on how human environments have changed across cultural and evolutionary histories, and how plasticity in child development allows humans to adapt to various forms of environmental threat, deprivation, and uncertainty. We also talk about Dorsa’s experimental and cross-cultural research on child decision-making, and how these adaptive behaviors also vary across environments, resource availability, and uncertainty. Dorsa describes how the field of developmental psychology is slowly moving away from WEIRD (Western, Educated, Industrialized, Rich, and Democratic) assumptions in order to gain a richer understanding of the full scope of child development across cultures.

Dr. Anita Collins is an award-winning educator, researcher and writer in the field of brain development and music learning. She is the author of The Lullaby Effect: The Science of Singing to Your Child and The Music Advantage: How Learning Music Helps Your Child’s Brain and Wellbeing.

In this episode we talk about the neuroscience of music education, and the brain and cognitive benefits of musical training in children and adults. Anita describes how music is unique in that it combines multiple modalities of the brain including auditory processing, visual processing, fine motor control, strategic planning, and creativity. We also discuss music as a means of social and mother-infant bonding, and evolutionary theories as to how music has emerged as an adaptation across every human culture.

Dr. Samuel Gershman is a Professor of Psychology at Harvard University, where he directs the Computational Cognitive Neuroscience Laboratory. He is also the author of What Makes Us Smart: The Computational Logic of Human Cognition.

In this episode we discuss Sam’s book, and the central argument that human brains are computers that must operate based on both limits of information and limits of computational power. These limits are what lead to biases, but Sam stresses that biases in human cognition, such as falling for optical illusions, are in fact what make us smart. We talk about some of the mechanisms by which we learn, such as statistical learning, and discuss the similarities and differences between human learning and modern artificial intelligence. We also discuss some of Sam’s theoretical research on the computational and neural mechanisms involved in learning and memory, and discuss how this model may apply to animals as simple and diverse as small planarian flatworms.

Dr. Frank von Hippel is a Professor of Ecotoxicology and Environmental Health Sciences at the University. He is the host of his own successful podcast, The Science History Podcast, and author of The Chemical Age.

In this episode we talk about Frank’s own field of ecotoxicology, the study of environmental toxins and their effects on humans and other animals, and Frank’s book The Chemical Age. We discuss the pros and cons of advancements in chemistry, from advancements in medicine and agriculture to chemical warfare and the environmental harms of industrialization. We also talk about what makes something a toxin, how our bodies respond differently to organic vs. synthetic compounds, and about the massive benefits and potential harms of pesticide use in modern agriculture. Lastly, we talk about Frank’s own research on how pollutants such as plastics harm humans and animals in the Arctic, and about both the threats of climate change to biodiversity and how we might overcome them.

Dr. Robert Epstein is a longtime psychology researcher and professor—a distinguished scientist who is passionate about educating the public about advances in mental health and the behavioral sciences. The former editor-in-chief of Psychology Today, Dr. Epstein is currently Senior Research Psychologist at the American Institute for Behavioral Research and Technology. He is also the founder and Director Emeritus of the Cambridge Center for Behavioral Studies in Massachusetts. He is also the author of The Case Against Adolescence, and its updated release Teen 2.0.

In this episode we discuss Dr. Epstein’s case against adolescence, the argument that historically, the social transition from childhood to adulthood was more rapid, and that the view of adolescence as a distinct phase of the lifespan is a relatively modern and Western concept. Dr. Epstein and I engage in a healthy debate on this topic, informed by my own research on adolescent development and the view that puberty marks a distinct and protracted period of physiological, neural, and psychological development.

In support of his argument Dr. Epstein discusses a wide-range of social and technological transformations impacting childhood development and our views on teenagers across the last two centuries, including industrialization, mandatory education, child labor laws, and more recently, social media and technology use. We additionally discuss positive steps towards promoting healthy development in teens, including individualized education, increased autonomy, and increased responsibility.

Dr. Jason Mitchell is a Professor of Psychology at Harvard University, where he directs the Social Cognitive & Affective Neuroscience Laboratory. His research uses a combination of neuroimaging and behavioral measures to investigate the cognitive processes that support inferences about the psychological states of other people and introspective awareness of the self.

In this episode we introduce social neuroscience as a field of research at the intersection between social psychology and cognitive neuroscience, and discuss the neuroscience of mindreading. Mindreading, in this context, refers to our social cognitive capacity for thinking about the thoughts and feelings of others, otherwise known as mentalizing or theory of mind. Jason and I discuss how mindreading relates to other processes such as introspection, and how mindreading may be accomplished either through mental simulation (placing oneself in another’s shoes) or heuristics. Next, we discuss Jason’s own research on the neuroscience of introspection and mindreading, and his findings that mindreading looks more similar to introspection in the brain when reasoning about others more similar to us. Lastly, we discuss more exotic forms of mindreading such as animal theory of mind and empathizing with inanimate objects or cartoons, and what these processes tell us about the cognitive mechanisms underlying mindreading and empathy.

Dr. Bryce Huebner is the Provost’s Distinguished Associate Professor of Philosophy at Georgetown University, where he conducts research connecting philosophy of mind, cognitive science, biology, and moral psychology.

In this episode we talk broadly about what it means to be conscious, and how cognition and emotion are governed by bodily processes. Bryce and I discuss how philosophy of mind ought to be informed by the biological limitations that give rise to complex thought, how much of our thought and behavior revolves around maintaining homeostasis and satisfying conflicting motivations, and how both nature and nurture give rise to individual differences in these processes. We also talk about the possibility for artificial intelligence and consciousness in non-human animals, and discuss the relationships between consciousness, life, and functionalism. Lastly, we discuss the concept of distributed cognition in Bryce’s book Macrocognition, and how this relates to moral psychology.

Dr. Randolph Nesse is a Professor Emeritus in the Departments of Psychiatry and Psychology, and the Institute for Social Research at The University of Michigan, and one of the pioneers of the field of evolutionary psychiatry. He is the Founding President of The International Society for Evolution, Medicine, and Public Health, and author of the book Good Reasons for Bad Feelings.

In this episode we talk about the field of evolutionary psychiatry, and more broadly about the evolution of both negative emotions such as fear and anxiety and positive emotions such as happiness. We talk about how humans have evolved with a “negativity bias” which primes us to sense threat, even in the case of false alarms, and how at the extreme this leads to anxiety disorders. On the other hand, we talk about how either a lack of positive emotion (depression) or excess positive emotion (mania) can be pathological, and how evolution must act to fine-tune our emotions for the right context. Overall, we have good reasons for bad feelings, but knowledge of why our emotions have evolved and what contexts they evolved in can help us fine-tune our emotions in our modern environments.

Find Dr. Nesse’s book and learn more about his work at: goodreasons.info

Dr. Steven Pinker is a Cognitive Scientist and the Johnstone Family Professor of Psychology at Harvard University. He is an elected member of the National Academy of Sciences, a two-time Pulitzer Prize finalist, a Humanist of the Year, a recipient of nine honorary doctorates, one of Foreign Policy’s “World’s Top 100 Public Intellectuals” and Time’s “100 Most Influential People in the World Today,” and the bestselling author of 12 books including The Language Instinct, How the Mind Works, The Blank Slate, The Better Angels of Our Nature, Enlightenment Now, and most recently, Rationality: What It Is, Why It Seems Scare, and Why it Matters.

In this episode we discuss Dr. Pinker’s latest book Rationality, and how rationality is best defined as using knowledge to achieve a particular goal. We talk about the distinction between rationality as expressed in formal logic and ecological rationality, why people (including hunter-gatherers) may fail at logic puzzles but excel at those same puzzles when applied to reasoning about social or resource dilemmas. We also discuss cognitive biases that interfere with rationality, such as the “myside bias” and how the availability heuristic distorts our memories, and how these biases may be overcome through looking at the world in data. Additionally, we discuss how many irrational beliefs, such as conspiracy theories, are not failed attempts at objective descriptions of the world, but rather beliefs constructed using a “mythology mindset” that attempts to convey a moral message. Lastly, we discuss how rationality relates to enlightenment values, and the case to be (cautiously) made for rational optimism.

0:00:50Motivation for writing the book0:03:43Defining rationality0:05:22How people can behave more rationally in real-life situations0:10:30The rationality of hunter-gatherers0:13:07The relationship between intelligence and rationality0:14:51The role of cognitive biases in irrationality0:19:39The influence of social factors on rationality0:24:07The scarcity of rationality and the spread of irrational beliefs0:30:57The role of memes and cultural evolution in irrational beliefs0:35:06The possibility of rationality being hijacked by parasitic ideas0:38:42The importance of trust in scientific and journalistic institutions0:43:12The connection between rationality and progress0:46:29The need for a cognitive immune system against irrational beliefs0:50:10The continuation of progress and setbacks in different areas0:54:38The connection between rationality and moral philosophy

Dr. Ilan Dar-Nimrod is an Associate Professor of Psychology at the University of Sydney, and an expert on how people reason about genetic causes of behavior, the psychology of gender and sexuality, and the existential psychology of death.

In this episode we talk about psychological essentialism, the belief that people have an innate “essence,” and how over time, as society has become more secular, people have become genetically essentialist. We talk about how genetic essentialism is associated with more sympathy for wrongdoers, due to lower beliefs in free will. We also talk about how essentialism is associated with divisive groupthink, as in the case of gender and sexuality. Lastly, we talk about the relationship between essentialism and existentialism, noting that people who are more essentialist are more likely to believe in an inherent order to the world, while people who are more secular must grapple with finding their own meaning.

Dr. Imac Zambrana is an Associate Professor of Education at the University of Oslo, and an expert in the study of children’s language development, social cognition, and social learning. She is also the Chief Scientific Officer at Nordic Neurotech, which aims to use virtual reality to help with psychological and medical research.

In this episode we discuss Imac’s research on childhood language development, and how this process is influenced by social learning, such as through the pointing gestures of parents. We also discuss children’s learning more broadly, including intrinsic and extrinsic motivations for learning, breadth vs. depth of knowledge, and how digital media has shaped children’s learning during the COVID-19 pandemic. Lastly, we discuss Imac’s work with Nordic Neurotech, including how virtual reality technology can be used to improve children’s educational outcomes, and how neuroimaging technology can be used in therapeutic medicine.

Dr. Valerie van Mulukom is an Assistant Professor at Coventry University’s Centre for Trust, Peace, and Social Relations, and a Research Associate at the University of Oxford’s Centre for the Study of Social Cohesion. Her research spans a broad range of topics, roughly unified within the cognitive and evolutionary science of imagination, memory, and belief.

In this episode we talk about Valerie’s early cognitive research on imagination and memory, and her more recent research on belief, including religious, secular, and conspiracy beliefs. We talk about how cognitive heuristics such as social learning bias evolved and shape our beliefs, how cultural evolution selects for specific beliefs, the role imagination plays in children’s play and intuitive science, and how we inevitably construct worldviews to explain the world - whether these worldviews are scientific, religious, or conspiratorial.

Dr. Anna Lembke is a Professor of Addiction Medicine at Stanford University, Program Director of the Stanford Addiction Medicine Fellowship, and Chief of the Stanford Addiction Medicine Dual Diagnosis Clinic. She is a diplomate of the American Board of Psychiatry and Neurology, a diplomate of the American Board of Addiction Medicine, and the bestselling author of the books Drug Dealer, MD – How Doctors Were Duped, Patients Got Hooked, and Why It’s So Hard to Stop, and Dopamine Nation: Finding Balance in the Age of Indulgence.

In this episode we talk about what dopamine is and how it governs the brain’s systems of pleasure and pain, how dopamine causes addiction (both with drugs and behaviors), how addiction has become a public health crisis in the United States, and what we can do about it. We talk about addictive technologies such as smartphones, and how this impacts today’s youth, and strategies for dopamine detoxification in order to promote happiness and well-being. Lastly, we discuss the difference between biological and sociological problems, and discuss Dr. Lembke’s warning against doctors overprescribing drugs and attempting to “biologize” non-biological problems.

Dr. Alan Levinovitz is an Associate Professor of Religion at James Madison University, and author of Natural: How Faith in Nature's Goodness Leads to Harmful Fads, Unjust Laws, and Flawed Science.

In this episode we talk about Alan’s book Natural, and attempt to understand why people gravitate towards assuming what is natural is good, what is unnatural is bad, and how people come up with ideas of naturalness in the first place. We contrast examples such as “unnatural” foods and medicines improving our lives, and “natural” diseases harming us, to make the case that what is natural may not be good, and what is unnatural may not be bad. We discuss historical and evolutionary reasons, including reducing uncertainty, for why humans tend to deify the natural and associate it with the good, as well as the philosophical implications of these differing worldviews, and how to cope with uncertainty.

Dr. Frans de Waal is a primatologist and the C. H. Candler Professor in the Psychology Department of Emory University and Director of the Living Links Center at the Yerkes National Primate Research Center. He has been elected to the (US) National Academy of Sciences, the American Academy of Arts and Sciences, and the Royal Dutch Academy of Sciences. He’s the author of several bestsellers including Chimpanzee Politics, Good Natured, Our Inner Ape, The Age of Empathy, Mama’s Last Hug, and most recently, Different: Gender Through the Eyes of a Primatologist.

In this episode, we talk about Dr. de Waal’s most recent book, Different, comparing and contrasting sex and gender differences amongst humans, chimpanzees, and bonobos. Chimpanzees are patriarchal, competitive, and aggressive; while bonobos are matriarchal, peaceful, and highly sexual. Humans are somewhere in-between. We talk about how the field of primatology evolved over the decades, especially during the feminist revolution, and how old views of human and primate evolution focusing on male-dominance and violent competition, rather than egalitarian cooperation, have gone out of fashion. We talk about the role human moral values play in shaping the behavioral sciences, both for good and for bad. Lastly, we talk about how understanding which gender differences are natural and which are socially constructed allows us to reduce sexism and discrimination.

Dr. Kim Meidenbauer is a social, cognitive, and environmental neuroscientist, Postdoctoral Research Fellow at the University of Chicago, and incoming Assistant Professor at Washington State University. Her research focuses on how the physical environment influences brain development, and in turn, our cognition, emotion, and social behavior.   

In this episode we talk about Kim’s research on how physical environmental stressors, such as heat exposure, influence our brains and predict social behavior, including crime rates. Additionally, we talk about the positive effects of greenspace, spending time in nature, on development and mental health, and how these effects can be measured using data gathered from smartphones and social media posts.   We talk about the question of free will: how free are we really, if our brains and behaviors are shaped by environmental and genetic influences? Lastly, we talk about the important policy implications of Kim’s research, especially as climate change accelerates and as we become more aware of the influence of the physical environment on our mental well-being.