1993 Kyoto Prize Laureates

Basic Sciences

Biological Sciences(Evolution, Behavior, Ecology, Environment)

William Donald Hamilton

/  Evolutionary Biologist

1936 - 2000

Professor, University of Oxford

Commemorative Lectures

Between Shoreham and Downe: Seeking the Key to Natural Beauty


11 /11 Thu

Place:Kyoto International Conference Center


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


11 /12 Fri

13:10 - 17:30

Place:Kyoto International Conference Hall

Achievement Digest

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).


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.


Born in Cairo, Egypt
B.S., St. John's College, Cambridge University
Ph. D., University of London
Lecturer, Imperial College, University of LondonVisiting Professor, Harvard University, Universidade de Sao Paulo, BrazilNine 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.

Profile is at the time of the award.