"Robert Axelrod's extraordinary book, "The Evolution of Cooperation "was globally acclaimed for the rich results of its simple model. "The Complexity of Cooperation" now gathers together the myriad fruits of more than a decade's work, carefully 'complexifying' his initial model. Like his ideas, his prose is clear and engaging. His delight as he unveils each surprising discovery is infectious. This book is not merely important; it's fun."--Robert D. Putnam, author of "Making Democracy Work"