Stefan:
>the book about cooperation is from Robert Axelrod, the title being
>"The Evolution of Cooperation", New York 1984. I bought a German trans-
>lation in 1992.

Or try "The Stone Age Present: How evolution has shaped modern life--from
sex, violence, and language to emotions, morals and communities" by William
F. Allman (1994 Simon & Schuster). This book has a great summary of
research on the Tit for Tat strategy of prisoner's dilemma as well as other
fascinations.

>It deals mainly with the "prisoner's dilemma", which was covered
>by Douglas R. Hofstadter in his "Metamagicum". (Did anyone read it?)

I _think_ it is called Metamagical Themas in the original English version.

Cheers,
Kirt

frisbee? It's fun is all ;)