The Nature & Nurture Podcast

Dr. Adriene Beltz is an Associate Professor of Psychology at the University of Michigan, where she directs the Methods, Sex Differences, and Development Lab.

Dr. Larry Young is the William P. Timmie Professor of Psychiatry at Emory School of Medicine, where he directs the Center for Translational Social Neuroscience and the Silvio O. Conte Center for Oxytocin and Social Cognition at Emory University. He is the author of The Chemistry Between Us: Love, Sex, and the Science of Attraction explores the latest discoveries of how brain chemistry influences all aspects of our relationships with others. Dr. Young’s research focuses on the role of oxytocin and vasopressin in mediating social bonding and sexual behavior across a wide range of species, with emphasis on understanding the evolution and neural circuit mechanisms underlying love, attachment, and social bonding in humans. 00:27 A Childhood Fascination with Animal Behavior

01:11 From Biochemistry to Behavioral Biology: A Scientist's Journey

02:14 Exploring the Sexual Behavior of Lizards

05:25 The Red Queen Hypothesis and Evolutionary Biology

08:02 Diving into Human Hormones and Brain Development

08:58 The Complex World of Gender and Sexuality in Nature

15:14 Unraveling the Mysteries of Love and Bonding in Voles

18:42 Oxytocin: The Hormone of Birth, Bonding, and Beyond

22:06 The Science of Touch and Social Connection

26:59 Understanding Love as a Form of Addiction

30:08 The Impact of Losing a Partner on Prairie Voles

31:56 Exploring Love and Addiction Through Oxytocin Studies

32:27 Debating Love: Chemical Reaction or More?

34:09 The Science of Attraction: Oxytocin's Role

37:01 Understanding Love and Bonding Across Species

41:28 The Intricacies of Sexual Behavior and Attraction

47:42 The Evolutionary Mechanisms of Mating and Bonding

59:41 Utilizing Science to Strengthen Relationships

Steve Rathjay is a Psychologist and Postdoctoral Research Fellow at the Social Identity and Morality Lab of New York University. He is an expert in the psychology of social media use and one of the leaders of the Global Social Media Experiment, an international collaboration examining the causal impact of social media usage in 76 countries around the world. Dr. Rathje received his PhD from the University of Cambridge as a Gates Cambridge Scholar, and completed his undergraduate education in Psychology and Symbolic Systems at Stanford University. He has received numerous grants and awards for his research, and runs the science communication channel @stevepsychology with more than 1 million followers on TikTok. 00:07 Exploring Social Media's Impact on Political Polarization

02:15 The Paradox of Virality: Why Negative Content Spreads

10:17 Evolutionary Perspectives on Social Media Behavior

14:50 The Creator's Dilemma: Navigating Virality and Authenticity on TikTok

36:07 The Science of Clickbait: Understanding What Captivates Us

40:41 The Power of Podcasts: Fostering Connection in the Digital Age

42:39 Exploring Parasocial Relationships and Social Media Dynamics

46:06 The Impact of Negativity Bias and Climate Doomerism

51:46 Social Media's Role in Global Connectivity and Cultural Evolution

01:14:11 The Power of Inoculation Theory Against Misinformation

01:22:13 Navigating the Complex Landscape of Social Media Regulation

01:28:50 Concluding Thoughts on Social Media's Societal Impact

Dr. Rob Henderson is a Psychologist, Air Force Veteran, and author of Troubled: A Memoir of Foster Care, Family, and Social Class. Expanding on our past episode, in which we discuss luxury beliefs, social status, and classism at length, this time our discussion is much more personal. In this episode, Rob and I discuss formative experiences written in his memoir, the impacts of childhood poverty on health and future success, the importance of self-discipline, the politics of diversity and inclusion in academia, trickle-down meritocracy, and much more. 

Dr. Sergio Pellis is a Professor of Neuroscience at the University of Lethbridge and one of the world’s leading experts in the neurobiology of play. 

In this episode, we discuss how play behavior across mammals relies on the same neural reward circuitry, the evolutionary origins and benefits of play, and how hormones contribute to sex differences in aggression, sexual, and play behavior. We also discuss connections between play across species and empathy, its impact on the development of social skills in children, and the impacts of social isolation on brain and cognitive development. 

00:15 The Neuroscience of Play: A Historical Perspective

04:01 The Evolutionary Purpose of Play

06:37 The Role of Reward Systems in Play

15:36 The Developmental Stages of Play in Animals

27:20 The Social Functions of Play

34:29 The Neurobiology of Play and Its Impact on Brain Development

35:54 The Impact of Play on Brain Development

36:41 Exploring Sex Differences in Play

37:49 The Role of Hormones in Play Behavior

39:20 The Influence of Rearing Environment on Play

39:40 The Shift in Play Tactics at Puberty

41:23 The Complexity of Sex Differences in Play

45:14 The Impact of Social Isolation on Brain Development

46:26 The Importance of Play for Both Sexes

50:11 The Influence of Play on Executive Functions

01:00:30 The Role of Pheromones in Social Interactions

01:08:15 The Impact of Play Deprivation on Brain Development

01:10:05 The Psychological Training Aspect of Play

01:11:08 The Empathy Developed Through Animal Research

Angel Millar is a hypnotist, martial artist, and author of The Path of the Warrior-Mystic: Being a Man in an Age of Chaos.

In this episode we discuss the balance between masculine and feminine traits, discipline and creativity, mind and body, and tradition and modernity. The warrior-mystic, Angel explains, represents the ideal balance between these traits, and we discuss historical examples including Greek philosopher-athletes, Japanese samurai-artists, and English knight-poets. We discuss the virtues of discipline and delayed gratification, how they apply to modern life amidst our panoplies of temptation, their relation to evolution and sexual selection, and the archetypal symbols in each of these motifs and in mythology. Lastly, we discuss Angel’s career as a hypnotist, and our formative experiences leading to our shared interests in psychology, mysticism, and traditional masculinity. 

00:24 Exploring Masculinity and Spirituality

02:14 The Warrior Mystic: Balancing Masculine and Feminine

03:07 Historical Shifts in Masculinity and Femininity

03:45 Impact of World Wars on Gender Roles

06:22 The Role of Archetypal Patterns in Culture

09:30 The Power of Anticipation and Delayed Gratification

12:15 Exploring the Benefits of Meditation

15:00 The Journey into the Unknown: Sir Gawain's Story

16:32 The Role of Boredom in Creativity

18:54 The Impact of Social Media on Honesty

23:13 The Intersection of Video Games and Personal Growth

25:17 The Importance of Balance in Personal Development

28:00 The Role of Risk-Taking in Personal Growth

30:24 The Power of Diverse Interests in Innovation

33:12 The Role of Creativity in Leadership

37:52 The Role of Masculinity in Modern Culture

38:32 The Dichotomy of Gender Roles

41:03 The Symbolism of Beheading in Art

43:43 The Phoenix Motif and Its Connection to Christ

45:50 The Influence of Past on Self-Improvement

52:27 The Role of Hypnotism in Self-Improvement

57:53 The Influence of Attractiveness on Self-Improvement

Dr. Lee Cronin is a Professor and the Regius Chair of Chemistry at the University of Glasgow, where he leads research on the chemical origins of life, computerized chemistry, and assembly theory. In this episode, we explore how assembly theory, analogues between chemistry and computation, the origins of life, the concepts of entropy and time, quantum mechanics, consciousness, simulation theories of the universe, and much more. 

00:32 Understanding Assembly Theory

01:47 Bridging the Gap: Physics, Chemistry, and Biology

03:27 The Role of Information Processing

04:24 Complexity in Biology and Neuroscience

06:02 Applying Assembly Theory to Molecules

08:57 Exploring the Origins of Life

18:16 Entropy and Complexity

22:21 Time and Selection

32:45 Quantum Mechanics and Uncertainty Principle

37:47 Heat Death State and Space as an Emergent Property of Time

39:07 Emergence of Space and Time

41:28 Randomness, Free Will and Consciousness

42:27 Panpsychism and Consciousness

52:45 Free Energy Principle and Neuroscience

58:38 Simulation Theories and Combinatorial Explosions

01:03:15 Scientific Anarchy and Progress

#Chemistry #Physics #Biology #AssemblyTheory #Consciousness #Simulation #Entropy #Time #Quantum #Selection #Evolution #FreeWill

Dr. Alex Byrne is a Professor of Philosophy at MIT and author of Trouble with Gender.

In this episode, we talk about the problematic concept of gender, which is often used interchangeably to mean sex, gender identity, gender role, gender norm, or gender stereotypes. Alex and I discuss each of these, and their precise definitions in philosophy, biology, or sociology in detail. We also discuss the problem of identity and categorization in philosophy of mind and language more broadly, as a source of some of the confusion. Lastly, we discuss the nuances of defining sex and gender in intersex and transgender populations, the essentialist nature of felt gender identity, the concept of transracialism, the ethics of social and medical gender transition in children, and answer the question: What is a woman? 

00:18 Understanding the 'Trouble with Gender'

02:19 Exploring the History of Gender Philosophy

05:07 The Role of Language in Defining Gender

05:46 The Complexity of Gender Terminology

10:16 The Misinterpretation of Gender Concepts

22:22 The Absurdity of Precise Definitions

41:33 The Biological Definition of Sex

58:18 The Hypothetical Cat-Dog: A Thought Experiment of Social Perception

01:02:32 Gender, Sex, and the Complexity of Identity

01:03:35 The Practical Implications of Defining Gender

01:05:51 Transgender Identity and the Question of 'Passing'

01:20:21 The Philosophical Dilemma of Pronouns and Gender Identity

01:22:33 Transracialism and the Social Construct of Identity

01:46:13 The Controversy of Autogynephilia and Gender Identity

01:53:29 The Reception and Impact of Controversial Philosophical Ideas

Dr. Wolfram Schultz is a Professor of Neuroscience at the University of Cambridge and one of the world’s leading experts on dopamine. In this episode, we discuss the dopamine system's role in reward processing, evolutionary fitness, the functioning of dopamine neurons, the interplay between reward vs punishment, and the complexity of neurons. Dr. Schultz overviews core mechanisms of value-guided decision-making, risk-taking, addiction, the role of prediction error in shaping reinforcement learning, how these are all explained by dopamine, and the differences between dopamine and serotonin 00:18 Understanding Reward Processing in Animals 01:29 Evolutionary Role of Reward System 03:31 Complexity of Reward System and Dopamine Neurons 04:31 Differentiating Reward and Avoidance Systems 05:35 Role of Emotion in Reward Processing 08:07 Exploring Consciousness and its Measurement 08:49 Dopamine Firing in Different Scenarios 11:41 Understanding the Complexity of Neurons 18:23 Exploring the Concept of Prediction Error 27:36 Understanding the Role of Dopamine in Depression 30:52 Understanding the Role of Serotonin and Dopamine 33:55 Exploring the Concept of Metacognition 43:28 Understanding the Development of Reward System in Humans 43:59 Understanding the Reward System in Infants 45:36 The Maturation of the Reward System 46:41 The Role of Neural Connections in Reward System 47:23 The Concept of Reward Sensitivity During Adolescence 48:44 The Importance of Exploration in Reward System 54:53 The Role of Dopamine in Reward System 01:02:41 Understanding Addiction and Dopamine's Role 01:02:45 The Impact of Modern Day Environment on Reward System 01:13:04 The Role of Risk in Assessing Subjective Reward Value 01:18:06 Understanding Individual Differences in Reward Sensitivity 01:20:14 The Never-Ending Journey of Incentive Reward #Neuroscience #Dopamine #RewardProcessing #BehavioralEconomics #Addiction #RiskTaking #NatureandNurture

Dr. Camilla Nord is a neuroscientist, leader of the Mental Health Neuroscience Lab at the University of Cambridge, and the author of The Balanced Brain: The Science of Mental Health.

In this episode we talk about The Balanced Brain, prediction error as the source of positive and negative emotion, how dopamine controls motion, motivation, and pleasure, how serotonin regulates mood and response to the social world, and how anti-depressants and anti-anxiety medications work on the brain. We also talk about the neuroscience of hallucinations in schizophrenia and on psychedelics, the role of homeostasis and the gut microbiome in regulating mood consciously and unconsciously, interactions between the brainstem and cortex in producing consciousness, the role of mindfulness in mental health, and much more. 

00:20 Understanding Emotions and Brain Processes

01:40 Exploring the Impact of Novelty and Curiosity

02:10 Introversion, Extroversion, and the Pandemic

03:16 Understanding Anxiety and its Role in Academia

05:05 The Balanced Brain: A Discussion on the Dynamic Nature of the Brain

06:56 The Influence of Predictive Processing on Mental Health

16:54 Exploring the Role of Psychedelics in Mental Health

21:22 The Interplay of Biology and Social Factors in Mental Health

23:22 Understanding the Role of Disgust in Mental Health

33:52 The Impact of Social Hierarchy on Mental Health

37:20 The Impact of Social Hierarchy on Academics

40:30 The Role of Dopamine in Motivation and Action Planning

42:11 Understanding Parkinson's Disease and Dopamine's Role

44:14 Differences Between Dopamine and Serotonin in Mental Health

45:30 The Effect of Antidepressants on Perception and Mood

47:55 The Role of Serotonin in Depression and Its Treatment

55:38 The Potential of Non-Invasive Brain Stimulation in Treating Depression

01:02:32 The Continuum of Mental Disorders and the Role of Genetics

01:11:37 The Role of Spirituality and Rationality in Mental Health

#neuroscience #mentalhealth #Medication #SSRIs #serotonin #dopamine #depression #psychopathology #society #videogames #brainbodyinteraction #CamillaNord #anxiety #schizophrenia #antidepressants #cognitivetherapy

Dr. Rachel Marsh is the Irving Philips Professor of Medical Psychology in Child Psychology at Columbia University Medical Center, where she runs the Cognitive Development and Neuroimaging Lab. Dr. Marsh studies the neurodevelopment of self-regulatory control and its pathology in disorders such as OCD, eating disorders, and Tourette’s syndrome. More recently, she studies how maternal stress contributes to intergenerational transmission of regulatory deficits.

Dr. Walter Veit is a Lecturer in Philosophy at the University of Reading and author of A Philosophy for the Science of Animal Consciousness. He is an expert in philosophy of mind, cognitive and biological sciences, applied ethics, and animal welfare.

In this episode, we talk about philosophy of mind and the evolution of consciousness in animals. Walter outlines his theory of the evolution of phenomenological complexity and affective experience in animals, its similarities and differences with computational theories of consciousness outlined by past podcast guests Kevin Mitchell and Mark Solms, and the diversity of consciousness ranging from humans, to other mammals, to octopuses and fish, to plant life and single cellular organisms. We discuss how animals’ capacity for experiencing pleasure and pain contribute to sentientist morality, whether human morality is anthropocentric, and how Walter’s research informs his views on animal welfare ethics.

Dr. Ellen Langer is a Professor of Psychology at Harvard University and one of the pioneers of the positive psychology movement, known as the Mother of Mindfulness. Dr. Langer has won numerous awards including 3 Distinguished Scientist Award, the Staats Award for Unifying Psychology, and the Liberty Science Genius Award. She is the author of 13 books on mindfulness, including 5 on mindfulness, most recently The Mindful Body.

Dr. Henning Tiemeier is a Professor of Social and Behavioral Science and the Sumner and Esther Feldberg Chair of Maternal and Child Health at the Harvard Chan School of Public Health. Dr. Tiemeier is an expert in pediatric epidemiology, focusing on prenatal exposures and the environmental determinants that influence brain development in children.

In this episode, we talk about pros and cons of different hormone measurement techniques and their use in pediatric epidemiology, neuroscience, and psychology. We also discuss how different environmental stressors, such as socioeconomic status and pollutants, impact brain and cognitive development prenatally, in early childhood, and during puberty. Lastly, we discuss neuroplasticity, and how public health research can intervene to improve the health and cognitive outcomes of at-risk populations during sensitive periods of development.

Dr. Willem Frankenhuis, he's an Associate Professor of Evolutionary and Population Biology at the University of Amsterdam, a Senior Researcher at the Max Planck Institute for the Study of Crime, Security, and Law, and Director of the Research Network on Communicating Strength-Based Approaches to Child Development and Learning in Adverse Conditions. He studies how cognition and behavior develop in harsh and unpredictable conditions. 

The episode delves into what constitutes a typical human childhood, drawing on insights from the intersection of human development, evolutionary biology, and cultural anthropology. 

We discuss 'hidden talents', abilities that adversity can enhance, and 'reasonable responses', behaviors that are adaptive strategies among individuals living in poverty. Dr. Frankenhuis also discusses his theoretical work involving mathematical modeling to study the evolution and development of plasticity – the ability to adjust development in response to different environmental conditions.

Dr. Lars Chittka is a Professor of Sensory and Behavioral Ecology and the founder of the Research Center for Psychology at Queen Mary University of London. He directs the Bee Sensory and Behavioral Ecology Lab, and is the author of The Mind of a Bee. In this episode, we discuss the results of decades of research on intelligence in bees and other insects. This includes findings of numerical and spatial cognition, memory, perception, and personality. Lars describes differences and similarities between bumblebees, wasps, and honeybees, why honeybees produce so much honey and die after stinging and mating, and more. We also discuss the evidence for bees having emotions, feeling, and consciousness, and efforts for the preservation and ethical handling of bees.

Dr. Jack Schultz is a Professor of Anthropology at Concordia University and an expert in the cultural anthropology of religion and sociology of knowledge.

Dr. Kevin Mitchell is an Associate Professor of Genetics and Neuroscience at Trinity College Dublin. He's the author of Innate: How the Wiring of Our Brains Shapes Who We Are, and Free Agents: How Evolution Gave Us Free Will. In this episode, we talk about Free Agents and the question of free will. We discuss what we mean by freedom, how living organisms have inherent biological constraints which actually define ourselves as causal agents. We also discuss the common scientific view of reductionist determinism and its limitations, and how causal agents use the inherent indeterminacy and forward motion of time in our universe as "causal slack" to make predictions and control their behavior in a meaningful way. We talk about the role entropy plays in life and computation, how free will grows as computational and cognitive complexity grows, and how these realities should define our ethical and legal conceptions of moral responsibility. Lastly, we talk about how individual differences in genes, environment, and brain development shape our personalities and constrain us in some ways, but also offer opportunities for unique identity, character development, meaning, and purpose.

Dr. Edward Hagen is a Professor of Evolutionary Anthropology at Washington State University, where he directs the Bioanthropology Lab. 

In this episode, Ed and I discuss the recent controversy of the American Anthropological Association’s decision to censor a conference panel on sex differences, the reality and importance of understanding sex differences in evolutionary anthropology and biology research, and the complexity of sex beyond the binary, such as in the case of intersex disorders and different and conflicting gender norms cross-culturally. We then move on to discuss Ed’s research on the evolution of substance use, including humans’ bizarre taste for spices and bitter plant toxins such as coffee and tobacco. We also talk about the evolutionary advantages and disadvantages for the use of other psychoactive drugs, such as hallucinogens, the evolution of human intelligence, and modern computational neuroscientific theories of consciousness.

Dr. Jennifer Silvers is an Associate Professor of Psychology and the Bernice Wenzel and Wendell Jeffrey Term Endowed Chair in Developmental Neuroscience at UCLA, where she runs the Social Affective Neuroscience and Development Lab. She is an expert in adolescent brain, cognitive, and emotional development, particularly in the development of emotion regulation strategies. 

In this episode, we talk about Jen’s background in developmental neuroscience, the use and limitations of animal models for understanding human brain development, and how adolescence is a particularly exciting window of brain development both due to puberty and other social and environmental changes. We talk about the role of stress and adversity influencing brain development, temperamental factors in emotion processing, emotion regulation as a learned skill, and how puberty interacts with all of these processes. We then discuss relatively recent effects on social and emotional development, such as the COVID-19 pandemic, social media use, and the influence of online dating apps in young adults’ sexual development. Lastly, we talk about other windows of rapid change influencing socioemotional processing, such as pregnancy, and future directions linking our shared interests in hormones and brain development in large-scale consortium-based studies.

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.