Figure 2
Experimental decision making by a single player and two non-cooperative players. (a) Schematic illustration of the casino setting: the reward probability of Machine B is higher (PB = 0.8) than that of Machine A (PA = 0.2) in the first 50 plays, whereas that of Machine A is higher (PA = 0.8) than that of Machine B (PB = 0.2) in the second 50 plays. (b) Decision making when only Player 1 plays the casino. (i) The CDR, which is the ratio of choosing the higher-reward-probability slot machine over the number of trials, adaptively approaches unity, meaning that Player 1 is making good decisions. (ii) The accumulated reward linearly increases over time. (c) Decision making when only Player 2 plays the machines. (d) Decision making when both Players 1 and 2 play the machines. The CDRs of both players adaptively approach unity; that is, both players choose the higher-reward-probability machine. However, making the same decision causes conflict between their decisions, limiting the rewards for each of the players as well as the team rewards (ii). (iii) The conflict ratio, which is the ratio of the occurrence of identical decisions by the two players over the number of trials.
