Task and data. (A) Trial sequence and payoff matrix in the Information Sampling Trust Game (ISTG). Before the participant made an investment decision, they could sequentially sample the decisions that the trustee made for other investors. On each trial, information could be sampled up to 25 times. The colour of the turned tile indicated the trustee’s past decision. Green = reciprocated trust, red = did not reciprocate trust, grey = not sampled. In the monetary cost conditions, 5 eurocents were deducted for each decision to sample (from a separate sampling budget of 125 eurocents per trial to keep the investment decision independent from sampling). In the monetarily free conditions, the 125 eurocents were always added to the trial outcome. Therefore, the monetarily costly condition did not have a higher gain. (B) Beliefs about the consequence of overt sampling. The most common belief amongst participants was that the more information they overtly sampled, the less likely reciprocation would become. Participants could choose from one of 3 categories: overtly sampling more information would make reciprocation less likely, more likely, or stay the same. (C) Sampling data which shows the effect of monetary cost and social context. Mean and SEM of drawn samples for each generative reciprocation probability per cost condition: green = covert sampling (trustee not informed), blue = overt sampling (trustee informed). (D) The proportion of investments increased with the probability of reciprocation for all conditions.