Decreased environmental variability induces a bias for social information use in humans☆

Individuals can use information gathered personally (individual information) or from others (social information) to track environmental change. Established mathematical models predict the rates of environmental change at which a social versus individual information gathering strategy would be adaptive, but the assumptions of these models, particularly the issue of individual flexibility in the strategy employed, have not been subject to rigorous empirical test. Participants (62 adult male and female humans) explored a virtual three-dimensional computer maze, with a forced choice between four reward locations. There were three low-value and one high-value reward, and monetary earnings were proportional to the total rewards located. The three experimental treatments were low, intermediate and high environmental variability, represented by the probability that the high-reward location moved between rounds. On the first 20 rounds, participants explored the maze alone. On the subsequent 80 rounds, participants could view a virtual player exploring the maze while exploring themselves. Participants exposed to the low environmental variability treatment tended to use social information, from the virtual player, more than players in the higher environmental variability treatments. These results are in line with the predictions of evolutionary models. Moreover, they suggest flexibility in information gathering strategies. Humans appear to assess current environmental variability and bias their reliance on social versus personal information accordingly.