Number of rewards obtained from both experimenters and subjects' net income according to the number of raisins returned by subjects.

Within one session, the subjects' net income, i.e. the amount of raisins non-invested by the subject plus those received after return. The subject maximises its gain by giving more (4 raisins, net income 8) to the doubling partner, and less to the fixed one (1 raisin, net income 11).