Leonid Viktorovich Krushinsky (1911–1984): Pioneer of the Biological Basis of Mind
Leonid Viktorovich Krushinsky was a titan of Soviet biology whose work bridged the gap between classical Pavlovian physiology and modern ethology. At a time when the study of genetics and "higher psychic functions" in animals was often politically fraught in the Soviet Union, Krushinsky pioneered a rigorous, experimental approach to understanding how animals think, reason, and inherit behavior.
1. Biography: A Life at Moscow State University
Leonid Krushinsky was born on June 16, 1911, in Moscow. His academic trajectory was remarkably stable in terms of location but revolutionary in terms of content. He entered Moscow State University (MSU) in the late 1920s, graduating from the Faculty of Biology in 1934.
He was mentored by some of the most brilliant minds of the era, including the developmental biologist Mikhail Zavadovsky and the legendary geneticist Sergei Chetverikov. This dual influence—physiology and genetics—would define his career.
Krushinsky spent his entire professional life at MSU. In 1953, he founded the Laboratory of Physiology and Genetics of Behavior, which became a sanctuary for objective behavioral research during the height of Lysenkoism (a period when Mendelian genetics was officially denounced in the USSR). Despite the political pressures, Krushinsky’s integrity and the undeniable empirical strength of his work allowed him to maintain his research program, eventually becoming a Professor in 1957 and a Corresponding Member of the USSR Academy of Sciences in 1974.
2. Major Contributions: The Theory of Elementary Reasoning
Krushinsky’s most significant contribution to science was his theory of Elementary Reasoning Activity (elementarnaya rassudochnaya deyatel’nost).
Elementary Reasoning vs. Conditioning
While Ivan Pavlov focused on conditioned reflexes (learning through association), Krushinsky argued that animals possess a capacity for "reasoning"—the ability to solve a novel problem on the first attempt by perceiving the laws governing their environment, without prior trial-and-error learning.
The Extrapolation Reflex
To test this, Krushinsky developed the "extrapolation task." An animal would watch a food bowl move along a track and then disappear behind a screen. To get the food, the animal had to predict (extrapolate) where the bowl would emerge on the other side. Krushinsky demonstrated that this ability varied wildly across species, with crows, dolphins, and foxes performing significantly better than many mammals typically considered "smart."
The Genetics of Behavior
Krushinsky was a staunch proponent of the idea that behavioral traits are inherited. He conducted extensive research on the inheritance of temperament and "reasoning" abilities, laying the groundwork for what is now known as behavioral genetics.
Audiogenic Seizures (The KM Rat Strain)
Along with his colleague L.N. Molodkina, he developed the Krushinsky-Molodkina (KM) strain of rats. These rats are genetically predisposed to have seizures in response to loud sounds. This became a vital model for studying epilepsy and the physiological limits of the nervous system under stress.
3. Notable Publications
Krushinsky was a prolific writer whose works were eventually translated, bringing Soviet ethology to the Western world.
- "Animal Behavior: Its Normal and Abnormal Development" (1960/English translation 1962): This seminal monograph synthesized his early findings on the intersection of genetics and behavior.
- "The Biological Bases of Psychic Activity" (1977): His magnum opus, which detailed his experiments on animal reasoning and argued for a biological continuity between animal intelligence and human thought.
- "Evolutionary-Genetic Aspects of Animal Behavior" (1991, posthumous): A comprehensive collection of his life’s work, published by his students and colleagues.
4. Awards & Recognition
Though Krushinsky worked behind the "Iron Curtain," his scientific rigor earned him high honors:
- Lomonosov Prize (1960): Awarded by Moscow State University for his pioneering work on the physiology of behavior.
- Lenin Prize (1988, posthumous): The highest scientific award in the Soviet Union, granted for his lifelong contribution to the study of the biological foundations of reasoning.
- Corresponding Member of the USSR Academy of Sciences (1974): A mark of his elite status in the Soviet scientific hierarchy.
5. Impact & Legacy
Krushinsky is considered the "Father of Soviet Ethology." His legacy is defined by three major impacts:
- Comparative Psychology: His "screen test" for extrapolation remains a standard experimental paradigm used today to test animal cognition across different taxa.
- The Survival of Genetics: By framing his genetic research through the lens of "higher nervous activity" (a Pavlovian term acceptable to the state), he helped keep the flame of Russian genetics alive during the Lysenko era.
- The Moscow School of Ethology: He trained a generation of scientists who continue to study the genetics of behavior and animal cognition in Russia and internationally. His work proved that "intelligence" was not a nebulous concept but a measurable biological trait shaped by evolution.
6. Collaborations
Krushinsky was a deeply collaborative figure who maintained a vibrant laboratory culture.
- N.V. Timoféeff-Ressovsky: The world-renowned geneticist was a close intellectual ally. Krushinsky often sought his counsel on the evolutionary implications of his behavioral data.
- Konrad Lorenz and Nikolaas Tinbergen: Although the Cold War limited travel, Krushinsky was aware of the work of these Nobel-winning ethologists. When Lorenz visited the USSR, he and Krushinsky found significant common ground, with Lorenz praising Krushinsky’s rigorous experimental proofs of innate behavior.
- L.N. Molodkina: His long-term collaborator in developing the KM rat strain, a partnership that spanned decades.
7. Lesser-Known Facts
- The Doberman Connection: Krushinsky was a passionate dog lover and a judge at dog shows. He used his own Doberman Pinschers in his early experiments on temperament and nervous system types, blending his hobby with his scientific rigor.
- A "Forbidden" Scientist: Because he insisted on the importance of genetics during the Lysenko period, he was often under surveillance. He reportedly kept his most controversial genetic data in private notebooks, only publishing them when the political climate thawed.
- The "Crow Intelligence" Pioneer: Long before modern studies on the "007" intelligence of New Caledonian crows became viral, Krushinsky was arguing in the 1950s that corvids (crows and ravens) possessed reasoning abilities equal to or greater than many primates.
- Artistic Soul: Beyond the lab, Krushinsky was known for his deep love of classical music and literature, often quoting Russian poetry to his students to illustrate complex biological concepts.
Conclusion
Leonid Krushinsky was more than a biologist; he was a bridge-builder. He connected the reflexology of the past with the cognitive science of the future. His work remains a testament to the idea that the "mind"—whether in a rat, a crow, or a human—is a product of biological evolution, governed by laws that can be discovered, measured, and understood.