ABSTRACT
Since the mid-1960's, inclusive fitness theory has revolutionized the study of animal behavior, and it promises far-reaching changes for the social sciences. The establishment of analytical principles will open the way to a synthesis of biological and social sciences if they succeed in showing the logic behind the evolution of aggressive motivation. Evolutionary biologists present a scenario of human behavior with little room for change because it relies on the assumption that behavior emerges from unmodifiable instincts. It is certainly true that animal behavior was once thought widely to be instinctual. Indeed the idea of an inborn aggressive drive was applied to humans and other animals. Animals are envisaged as having a finite set of possible strategies which they use in interactions with each other. The best strategy set depends on what other individuals do. Game theory has been applied extensively to animal contests using simple assumptions.
