Table 1.

Sample characteristics and descriptive data per time point.

	Baseline	Follow-up 1	Follow-up 2	Across time points
Sample characteristics
N	514	48	514
Gender (m/f)	259/255	24/24	259/255
Age	18.81 (2.96)	19.30 (2.87)	20.27 (2.98)
Outcome-irrelevant learning
woutcome-irrelevant				0.23 (0.09)
αoutcome-irrelevant				0.29 (0.23)
First-stage score	0.03 (0.12)	0.04 (0.11)	0.04 (0.10)
Second-stage score I	0.04 (0.15)	0.04 (0.14)	0.03 (0.12)
Second-stage score II	0.15 (0.27)	0.12 (0.24)	0.16 (0.22)
Model-based control
wmodel-based				0.38 (0.20)
First-stage score	0.10 (0.25)	0.08 0(0.23)	0.12 (0.20)
Second-stage score (ms)	120 (110)	110 (90)	130 (100)

Outcome-irrelevant learning: w_{outcome-irrelevant} reflects the weight of the response key cached value on the individual’s trial-by-trial decisions (units are arbitrary and should be interpreted in terms of being negative, zero, or positive; see Supplementary Information, Eqs. 6 and 7), estimated using computational modeling across all three time points. α_{outcome-irrelevant} is the learning rate for the response key cached value (range is between 0 and 1; see Supplementary Information, Eqs. 3 and 4), estimated across all three time points. First-stage and second-stage score I estimates are depicted as unstandardized regression coefficients, representing the effect of outcome in the previous trial (rewarded vs. unrewarded) on the probability of making the same response key choice (see Fig. 3). Second-stage score II shows the unstandardized regression coefficients of the previous outcome × mapping interaction estimate on the probability of making the same response key choice (Supplementary Fig. S1). Model-based control (w_model-based) reflects the weight of model-based strategies on an individual’s first-stage choices (units are arbitrary and should be interpreted in terms of being negative, zero, or positive; see Supplementary Information, Eq. 6). The first-stage score shows the unstandardized regression coefficients of the previous reward × previous transition interaction effect on the probability that individuals will repeat their first-stage fractal choice (see Supplementary Fig. S2). Second-stage score II reflects the difference in reaction time for second-stage choices after a rare compared to a common transition (see Supplementary Fig. S2).