Podcast Summary: "Who Taught Beavers to Build Dams?"

Podcast Information:

• Title: Unexplainable
• Host/Author: Vox
• Episode: Who Taught Beavers to Build Dams
• Release Date: July 21, 2025

Introduction

In the July 21, 2025 episode of Unexplainable, Vox delves into the enigmatic world of animal behavior, challenging the conventional notion of "instinct." Hosted by Noam Hassenfeld, the episode features an in-depth conversation with Dr. Mark Blumberg, a Behavioral Neuroscientist, who critiques the simplistic use of the term "instinct" in explaining complex animal actions such as spiders spinning webs, birds migrating, and beavers building dams.

The Concept of Instinct: A Historical Perspective

Dr. Mark Blumberg begins by tracing the origins of the term "instinct," highlighting its deep-seated roots in both scientific and religious contexts.

• Religious Origins: Blumberg explains that the concept of instinct historically intertwined with religious debates about free will and the afterlife. He states, “[Instinct] has its roots in a sort of a religious perspective” (04:31). The necessity to explain animal behavior without attributing free will led early thinkers to label such actions as instinctive.

• Scientific Adoption: The term was later appropriated by scientists like Konrad Lorenz, a pioneer in ethology, the study of animal behavior in natural contexts. Lorenz’s famous experiments on imprinting in ducklings, where chicks follow the first moving object they see, often the researcher, reinforced the idea that certain behaviors are hardwired or "instinctive" (05:34).

Challenging the Instinct Paradigm

Blumberg argues that labeling behaviors as instinctive oversimplifies the intricate interplay between genetics and environmental factors.

• Imprinting Revisited: He critiques Lorenz’s simplistic switch analogy for imprinting, suggesting that the process is multi-faceted, involving both genetic predispositions and learning experiences (06:07). For example, Gilbert Gottlieb’s research revealed that chicks developing vocalizations within the egg are essential for their later attraction to maternal calls. Rats gestated in space, devoid of Earth’s gravitational cues, failed to exhibit the "writing reflex," landing on their backs instead of their feet, demonstrating that what was thought to be an innate behavior is heavily influenced by environmental factors (09:32).

• Environmental Influence on Behavior: Blumberg emphasizes that behaviors like dam-building in beavers are not purely instinctual but emerge from interactions with their specific environments. He notes, “The environment is part of the inheritance of every species” (11:56), highlighting that environmental contexts shape what are often perceived as species-typical behaviors.

• Case Studies:

  • Squirrels and Digging Behaviors: Even when isolated from typical environments, squirrels exhibit digging motions, which are often dismissed as instinctive. Blumberg suggests that these behaviors may result from less obvious developmental experiences rather than purely genetic programming (12:20).
  • Cuckoos and Cowbirds Identification: Ernst Meyer’s assumption that species-specific identification is genetically encoded is challenged by evidence showing that social interactions, such as bullying by adult birds, play a crucial role in young birds learning to identify their species (13:15).

The Dangers of the Instinct Label

Blumberg warns that the uncritical use of "instinct" stifles scientific inquiry and perpetuates misconceptions.

• Hindrance to Scientific Progress: By labeling behaviors as instinctive, scientists may prematurely conclude explanations, halting further investigation into underlying mechanisms. Blumberg asserts, “Science is supposed to be asking the next question, and you just will never ask the next question if you label it as instinct” (03:33).

• Comparisons to Creationism: He draws a parallel between the overuse of "instinct" and creationist thinking, suggesting that both rely on simplified explanations to account for complex phenomena. Blumberg states, “It's no different than being a creationist” (15:21), pointing out that both approaches avoid embracing the full complexity of biological development.

• Ethical Implications: The misuse of instinctive explanations has historical repercussions, such as Lorenz’s promotion of eugenics. Blumberg connects this misuse to broader ethical issues, noting that such beliefs can have dangerous societal impacts (24:45).

Advocating for a Nuanced Understanding

Blumberg champions an integrated approach that considers both genetic and environmental factors in shaping behavior.

• Acquired Nature: He introduces the concept of an “acquired nature,” emphasizing that behaviors result from the combination of genetic predispositions and experiential learning. “We all have this ability to drink. It's essential. If we don't drink, we die, but we acquire it” (20:58).

• Plasticity in Development: Highlighting human adaptability, Blumberg references individuals like Johnny Eck, a man born without functional legs who learned to walk using his arms, demonstrating that complex behaviors arise from learning and adaptation rather than rigid genetic programming (22:07).

• Reconceptualizing Genetic Influence: While acknowledging the crucial role of genes, Blumberg argues against the dichotomy of nature versus nurture. “Genes evolved and function expecting a certain environment” (10:43), he explains, stressing that understanding behavior requires considering how genes and environments interact dynamically.

Implications for Scientific Research

The episode underscores the importance of resisting oversimplified labels in scientific terminology to foster deeper understanding and innovation.

• Resource Allocation and Recognition: The misuse of terms like "instinct" can influence which research receives attention and funding, potentially sidelining more nuanced studies that explore the complexities of behavior (25:30).

• Case of Sleep Twitches: Blumberg’s research on sleep-related twitches challenges the notion that such movements are mere byproducts of dreaming. He discovered that these twitches significantly activate brain activity during early development, a connection that would have been overlooked if the behavior were dismissed as instinctive (27:18).

• Encouraging Inquisitiveness: By avoiding reductive explanations, scientists can explore the diverse mechanisms that drive behavior, leading to a richer and more accurate understanding of animal and human actions (27:21).

Conclusion

The episode "Who Taught Beavers to Build Dams?" offers a compelling critique of the traditional concept of instinct in animal behavior. Through Dr. Mark Blumberg’s insights, listeners are encouraged to adopt a more integrative approach that recognizes the symbiotic relationship between genetics and environment in shaping complex behaviors. This shift not only advances scientific inquiry but also prevents the perpetuation of harmful ideologies rooted in oversimplified explanations.

Notable Quotes:

• “Instinct is basically a covert expression of ignorance and lack of imagination.” – Mark Blumberg [02:42]
• “It's no different than being a creationist.” – Mark Blumberg [15:21]
• “We all have this ability to drink. It's essential. If we don't drink, we die, but we acquire it.” – Mark Blumberg [20:58]

Further Reading and Resources

Listeners interested in exploring this topic further can refer to Dr. Blumberg’s books:

• Basic Instinct
• Freaks of Nature
• Development: The Origins and Meanings of Instinct (a shorter academic paper)

For more insights and discussions on animal behavior and other scientific mysteries, visit Unexplainable.