1993Basic SciencesBiological Sciences (Evolution, Behavior, Ecology, Environment)
William Donald Hamilton photo

William Donald Hamilton

  • U.K. / 1936-2000
  • Evolutionary Biologist
  • Professor, University of Oxford

Proposal of Inclusive Fitness and the Establishment of Evolutionary Theory of Sociality and Cooperation

An evolutionary biologist who proposed the concept of "inclusive fitness," to explain the evolution of altruistic behavior in animals that had been a persistent dilemma since Darwin's time. He beautifully revealed that an individual can increase the number of descendants carrying its own genes by helping and raising its own kin. He also gave a new aspect to the theory of the sex ratio, whereby a mother manipulates the sex of the eggs she lays in order to maximize her own inclusive fitness. His extremely cogent ideas had a revolutionary influence on the whole field of biological sciences.
*This field then was Field of Biological Sciences (Heredity, Development, Evolution, Ecology).


Brief Biography

Born in Cairo, Egypt
B.S., St. John's College, Cambridge University
Ph. D., University of London
Lecturer, Imperial College, University of London
Visiting Professor, Harvard University, Universidade de Sao Paulo, Brazil
Nine months in Brazil with Royal Society and Royal Geographic Society, Xavantina-Cachimbo Expedition
Professor of Evolutionary Biology, University of Michigan
Royal Society Research Professor, Oxford University, Department of Zoology

Selected Awards and Honors

Foreign Honorary Member of American Academy of Arts and Sciences
Fellow of the Royal Society of London
Newcomb Cleveland Prize of American Association for the Advancement of Science
Darwin Medal of the Royal Society of London
Scientific Medal of the Linnean Society
Frink Medal of Zoological Society of London

Major Works


The Genetical Evolution of Social Behavior I & II. Journal of Theoretical Biology 7., 1964.


Extraordinary Sex Ratios. Science. 156., 1967.


Altruism and Related Phenomena Mainly in Social Insects. Annual Reviews of Ecology and Systematics. 3., 1972.


Sex versus Non-sex versus Parasite. Oikos. 35, 1980.


The Evolution of Cooperation. (with Axelrod, R.) Science. 211., 1981.


Heritable True Fitness and Bright Birds: A Role for Parasites? (with Zuk, M.) Science. 218., 1982.


Proposal of Inclusive Fitness and the Establishment of Evolutionary Theory of Sociality and Cooperation

Dr. William Donald Hamilton is a renowned behavioral ecologist who has exerted a revolutionary impact on conventional biological sciences with his concept of “inclusive fitness,” which shed light on the evolution of altruistic behavior, and other extremely influential theories in evolutionary biology, such as expansion of the theory of sex ratio.

The thrust of Darwin’s theory of evolution based on natural selection is that better adapted individuals are able to produce more offspring, and therefore better adapted individuals tend to increase, resulting in the evolution of a highly adapted species. Thus, the general view was that each individual behaves selfishly in order to reproduce itself. However, worker bees and ants do not bear eggs, but nurture the queen’s eggs. Such “altruistic behavior,” which seems to be disadvantageous in enhancing the individual selection, and was for a long time difficult to explain in the context of evolution.

In 1964, Dr. Hamilton developed the concept of “inclusive fitness” and solved the century-old puzzle. Dr. Hamilton has mathematically and precisely proven that a certain percentage of one’s blood relatives possess identical genes to oneself, and thus one can also ensure the increase of one’s descendants by helping and fostering one’a close relatives. For this reason, in the animal world, each individual behaves in a way that enhances its inclusive fitness. This is our understanding today. The model advocated by Dr. Hamilton conforms to reality extremely well, and his theory of kin selection has not only provided a good explanation for the evolution of sterile individuals in social insects, but has also cleared the way for applying the concept of “inclusive fitness” to all life forms. Furthermore, in 1967, Dr. Hamilton proposed a model of “local mating competition” to explain the extreme imbalance of sex ratio in bees and other insects, and greatly advanced the study of animal sex ratios through analysis based on the game theory.

The series of studied by Dr. Hamilton has caused a great transformation in the biological sciences of behavioral science and ecology and has given birth to new fields of study, such as behavioral ecology and social ecology. Even today, Dr. Hamilton’s influence continues to spread into other fields, including anthropology, genetics, embryology, and cytobiology.

Due to such outstanding achievements, Dr. William Donald Hamilton is most eligible for the 1993 Kyoto Prize in Basic Sciences.


Abstract of the Lecture

Between Shoreham and Downe: Seeking the Key to Natural Beauty

A lifelong inclination to science comes to me both via nature and via nurture from my parents. I grew up near London but my parents were returned New Zealanders, my father an engineer and my mother a doctor. They believed in a pioneer-like independence for their large family, an ethos that was quite unusual in the London-commuter middle-class milieu where we lived. They applied their ideas both in the rules they mad for their children and in their insistent non-reliance on outside services, and purchases. My childhood home was a house on the edge of country, with a large garden and access to woods and fields. It was conductive to what may have been innate interests in natural patterns and in living things. I mention my introverted, weakly social, and object-oriented nature as a child and argue that this was an important in making me become a scientist. I claim also that appreciation of beauty, which in the best case should be natural beauty, is always important in determining the line and depth of a scientist’s work.

From my father I learned tool use, how to design and build things, and an introduction to some intriguing but unrigorous ideas of mathematics. Following his spatial, mathematical, and can-do-somehow talents was to be of great value to me in the development of the theoretical side of my later work. Where my father built physical models to illustrate his engineering ideas, I later built theoretical ones. My models, like his, are often makeshift and amateur D also like his, they work and they produce results that could not otherwise be known.

From my mother I leaned natural history, biology, and aesthetic appreciation. Specially from her I had an Extremely early introduction to the theory of evolution by natural selection, and from the moment I grasped the idea, evolution became an ever more consuming interest.

I describe how I came to know of two eminent neighbors of the Victorian era who had lived within a few miles of my childhood home. One was Charles Darwin himself and the other an artist, Samuel Palmer. The latter, I found, had painted visionary, utopian versions of the landscapes that I knew well. I link these admired forbears to two sides of my interests and personality. Darwin’s influence is paramount for any evolutionist and in my case I feel that I carried on almost from where he left off on the subject of social evolution. This work concerns the patterns and limitations that apply to social life in the living world generally. Palmer on the other hand represents my interest in what humans specially can expect achieve, their religious aspiration, and their ideal state of being. But for me all answers still must be based on models that, like my father’s, really work. This was a challenge that I believe Palmer never met, and this failure led to his disillusion and a decline in the conviction of his art. He ended a much more ordinary artist than he began. Seen in the context of current sentiments, the challenge is indeed harsh, but it is not obvious that a switch cannot be made into a different ethos, to another set of sentiments that may entail in the long run greater human happiness and security.

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Behavior, Ecology, and Evolution: Inclusive Fitness in the Real World

Friday, November 12, 1993
Kyoto International Conference Hall
Eiji Kuno (Member, Kyoto Prize Committee in Basic Sciences; Professor, Faculty of Agriculture, Kyoto University)


Greetings Toyomi Inamori; Managing Director, The Inamori Foundation
Greetings Heisuke Hironaka; Chairman, the Kyoto Prize Committee in Basic Sciences;
Professor Emeritus, Kyoto University
Introduction of the Laureate Toshitaka Hidaka; Chairman, the Kyoto Prize Screening Committee in Basic Sciences;
Professor Emeritus, Kyoto University
Commemorative Lecture William Donald Hamilton; Laureate in Basic Science
"Sex, Health and Social Behavior: Search for a Unifying Theory"
Lecture Shigeyuki Aoki; Professor, General Education Program, Rissho University
"Aphid Societies: Open or Closed"
Lecture Yoshiaki Ito; Professor, School of Arts and Science, Okinawa University
"Origin of Multi-Queen colonies in Eusocial Wasps: Lessons From The Genus Ropalidia"
Lecture Norio Yamamura; Assistant Professor, Saga Medial School
"Conflict and its Resolution between Relatives"
Lecture Youko Yamaguchi; Researcher, Hokkaido Forestry Research Institute
"Hamilton's Sex Raito Theory: Evidence and Extensions"
Lecture Yasuhiro Nakashima; Research Fellow, Faculty of Science, Kyoto University
"Sex Change; Theories and Facts"
Lecture Tetsukazu Yahara; Associate professor, Department of Biology, University of Tokyo
"Evolution of Selfing and Agamospermy in Flowering Plants"
Lecture Yoh Iwasa; Member, the Kyoto Prize Screening Committee in Basic Sciences;
Professor, Faculty of Science, Kyushu University
"The Evolution of the Number of Sexes"
Question and Answer