A 5 by 2 by 2 design was used to investigate the effects in the PDG of giving an advantage to one of the players of an original stake of 0, 25, 50, 100, or 500 points under two levels of conflict intensity. The 216 Ss were assigned to like-sex dyads. The results showed that the 25 point OS Ss cooperated more and as dyads produced fewer DD outcomes than the other OS Ss. The high conflict condition produced more defections, more DD outcomes, fewer CC outcomes, and fewer CD outcomes than the low conflict condition. Finally, female dyads had more CC outcomes than males.