The psychobiology of aggression: Engines, measurement, control : edited by Marc Hillbrand and Nathaniel J. Pallone The Haworth Press, Inc. (10 Alice Street, Binghamton, New York 13904-1580), 1995, 243 pp., hardcover — $49.95

We experimentally investigate team behavior in repeated public goods games and use team chat logs to study motives for contribution. Subjects are matched into two-person teams, and each team makes a joint decision in each period. We compare teams with individuals and find similar overall contributions. However, initial contribution is higher and endgame effects are more pronounced for teams. We examine strategic discussions within teams and find strong evidence of concern for repeated game effects and limited backward induction. We also find evidence of confusion and explore its potential sources.