Richard D. Alexander was one of the 20th century’s most influential evolutionary biologists, a man whose intellectual journey began with the chirping of crickets and culminated in a profound, often controversial, understanding of the human condition. As a pioneer of sociobiology and evolutionary psychology, Alexander’s work bridged the gap between rigorous entomology and the complex study of human morality and social structure.
1. Biography: From the Farm to the Ivory Tower
Richard "Dick" Alexander was born on November 18, 1929, in White Heath, Illinois. Raised in a rural environment, his early intimacy with nature informed his observational skills as a scientist. He attended Blackburn College before moving to Ohio State University, where he earned his Ph.D. in 1954, focusing on the systematic and behavior of crickets.
In 1957, Alexander joined the faculty at the University of Michigan, an institution he would call home for the remainder of his career. He served as a Professor of Biology and the Curator of Insects at the Museum of Zoology. Over four decades, he transitioned from being the world’s leading authority on singing insects to a central figure in the "Darwinian Revolution" of the 1970s, which sought to apply evolutionary logic to all social behavior. He passed away on August 20, 2018, leaving behind a legacy as a "biologist’s biologist."
2. Major Contributions: Predicting the Unknown
Alexander’s career is marked by three distinct pillars of intellectual achievement:
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Acoustic Communication and Speciation
In his early career, Alexander revolutionized the study of crickets and cicadas. He demonstrated that insect "songs" were not merely background noise but precise evolutionary tools used for species recognition and mate selection. His work provided a roadmap for understanding how behavioral changes can lead to the formation of new species.
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The Prediction of Eusocial Mammals
Perhaps his most famous "intellectual feat" occurred in the mid-1970s. By analyzing the ecological conditions that led to "eusociality" (the ultra-cooperative social structure of ants and bees), Alexander created a theoretical profile for what a eusocial mammal would look like: it would need to live in a safe, expandable nest, subsist on large tubers, and face high predation pressure outside the burrow. He was subsequently informed that the Naked Mole Rat (Heterocephalus glaber) fit this exact description—a stunning validation of the predictive power of evolutionary theory.
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The Biology of Morality and Indirect Reciprocity
Alexander was a primary architect of the theory of indirect reciprocity. While direct reciprocity is "I scratch your back, you scratch mine," indirect reciprocity is "I scratch your back, and someone else (who saw me do it) will scratch mine." He argued that human morality and our obsession with reputation evolved as a result of these complex social dynamics, driven by the need for group cohesion in the face of inter-group competition.
3. Notable Publications
Alexander was a prolific writer whose books remain foundational texts in evolutionary biology:
- "The Evolution of Social Behavior" (1974): A seminal review paper in the Annual Review of Ecology and Systematics that helped lay the groundwork for the field of sociobiology.
- "Darwinism and Human Affairs" (1979): In this work, he argued that human culture and social structures are not "exempt" from biology but are instead products of the same evolutionary pressures that shape other species.
- "The Biology of Moral Systems" (1987): Arguably his most important book, it explores the evolutionary origins of right and wrong, suggesting that morality is a sophisticated system of social manipulation and cooperation designed to help individuals navigate the "interests" of their groups.
- "The Singing Insects of Michigan" (1972): A testament to his roots as a meticulous field naturalist.
4. Awards & Recognition
Alexander’s contributions were recognized by the highest echelons of the scientific community:
- National Academy of Sciences: Elected as a member in 1974.
- Daniel Giraud Elliot Medal (1971): Awarded by the National Academy of Sciences for his work on the evolution of behavior.
- Distinguished Faculty Achievement Award: From the University of Michigan, honoring his dual role as a researcher and educator.
- President of the Society for the Study of Evolution: Reflecting his leadership in the broader biological community.
5. Impact & Legacy
Alexander’s legacy is twofold. First, he was a key figure in the Sociobiology debates of the 1970s and 80s. Alongside figures like E.O. Wilson and W.D. Hamilton, he faced intense criticism for suggesting that human behavior had a genetic basis. However, his rigorous, data-driven approach helped the field survive its early controversies to become what is now known as Evolutionary Psychology.
Second, his focus on "the levels of selection" helped clarify that evolution acts primarily on individuals and their genes, rather than for the "good of the species." This shift in perspective was vital for modern understandings of altruism, conflict, and family dynamics.
6. Collaborations and Mentorship
Alexander was a legendary mentor. His "Alexander Lab" at Michigan produced some of the most influential biologists of the next generation, including:
- Mary Jane West-Eberhard: A leading theorist on phenotypic plasticity.
- Paul Sherman: Who famously went on to study the naked mole rats Alexander had predicted.
- David Buss: A founding father of modern evolutionary psychology.
- Bernie Crespi: A major figure in the study of social evolution and genomic imprinting.
He maintained a long-standing intellectual dialogue with W.D. Hamilton, the father of "inclusive fitness" theory, often refining Hamilton’s mathematical ideas through the lens of behavioral ecology.
7. Lesser-Known Facts
- The "Hypothetical Animal" Lecture: In 1975, before he knew about naked mole rats, Alexander gave a series of lectures describing a "hypothetical eusocial mammal." When mammalogist Jennifer Jarvis later showed him the data on naked mole rats, he reportedly remarked that it was the most exciting moment of his scientific life.
- A Naturalist’s Heart: Despite his high-level theoretical work, Alexander remained a hands-on naturalist. He spent decades recording insect sounds in the wild, and his collection of over 100,000 insect specimens remains a vital resource at the University of Michigan.
- The "Balance of Power" Theory: Alexander proposed that the primary driver of human brain evolution was not tool use or hunting, but other humans. He argued that as humans became their own "principal hostile force of nature," we entered an evolutionary arms race for social intelligence, leading to the rapid expansion of the human cranium.
Richard D. Alexander’s work serves as a reminder that the same laws of nature that govern the smallest cricket also govern the highest aspirations of human society. He did not see biology as a cage, but as a lens through which we could finally see ourselves clearly.