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