The paper presents an expository account of several experimentally based descriptive theories of cooperation in interactive decision situations. First the equity principle (Selten 1988), prominence in the decimal system (Albers and Albers 1983), and the difference measure of predictive success (Selten 1991) are explained. Then the theory of equal division payoff bounds (Selten 1987) for zero-normalized three-person games in characteristic function form is presented and its predictive success is compared to that of the bargaining set (Aumann and Maschler 1964) and its modifications (Maschler 1978). The theory of the negotiation agreement area (Kuon and Uhlich 1993) for two-person characteristic function games with non-zero one-person coalition values is described and discussed with respect to its predictive success. The aspiration balance principle (Tietz and Weber 1972) and its dynamic elaborations, the planning difference theory and the dynamic balance aspiration theory (Tietz 1975, 1976) are explained and examined with respect to empirical support. The next topic is the empirical relevance of the minimal core for cooperatively played 3x3x3-games (Ostmann 1988) Finally, results of a strategy study on a repeated asymmetric Cournot duopoly (Selten, Mitzkewitz, and Uhlich 1988) are described and the structure of typical strategies programmed by subjects is discussed. This structure involves a cooperative goal and its active pursuit by what is called a measure-for-measure policy.
