In this study we present the results of a laboratory decision making experiment. We base our experiment on a simple manufacturer-retailer scenario where the consumer demand is random and revenue sharing contract is used. The experiment is based on a 2x2 between-subjects design. Subject either make retailer decisions, or manufacturer decisions and either make these decisions as individuals or in groups of three. Subjects undertaking the role of the retailer make ordering decisions against predetermined combinations of wholesale price and revenue share values. Subjects undertaking the role of the manufacturer, make contract parameter decisions against the computer program which orders the optimal quantity corresponding to the manufacturers' contract parameters. We analyze how group decisions compare to individual decisions in terms of supply chain contract and order quantity decisions. Additionally, we investigate how gender composition of the groups affect experiment performance.