Table 1. Probabilities and magnitudes of reward for the two prospects in each trial, for the 14 experimental conditions and the 3 control conditions.

Experimental Conditions
Reward Magnitude (coins)		Reward Probability (%)		EV	EV	EV Ratio
Prospect 1	Prospect 2	Prospect 1	Prospect 2	Prospect 1	Prospect 2
1	4	60	40	0.6	1.6	−0.909
1	5	70	30	0.7	1.5	−0.727
1	4	70	30	0.7	1.2	−0.526
2	5	60	40	1.2	2.0	−0.500
1	3	70	30	0.7	0.9	−0.250
1	5	80	20	0.8	1.0	−0.222
3	5	60	40	1.8	2.0	−0.105
3	4	60	40	1.8	1.6	0.117
4	5	60	40	2.4	2.0	0.182
1	3	80	20	0.8	0.6	0.286
2	3	70	30	1.4	0.9	0.435
3	4	70	30	2.1	1.2	0.545
1	2	80	20	0.8	0.4	0.667
2	3	80	20	1.6	0.6	0.909

Prospect 1 was arbitrarily designated as having the higher reward probability (EV = expected value = probability X magnitude).