Experimental task.
On each trial, participants choose whether to stay at the current tree and harvest or to switch to the next tree. Each subsequent harvest of the same tree resulted in a slightly decreased outcome and switching comes with the cost of travel time. Initial richness of trees and depletion rate differed between trees, but were equally distributed in environments with long and short travel times, respectively.On each trial, participants submitted their choice via button press, using the down arrow for harvesting the currently displayed tree and the right arrow for moving on to the next tree. A white dot appeared under the tree indicating that a decision should be placed. If the participant decided to harvest the tree, the number of harvested apples was displayed after a harvest time of three seconds, followed by the white dot asking for the next decision. If the participant chose to switch to the next tree, the dot turned black and the way to the next tree was displayed, either for 6 s or for 12 s, depending on the environment.Decisions had to be placed within 1 s, otherwise a warning appeared, followed by a short timeout before the next decision could be submitted. With each repeated harvest of the same tree, the yield of the tree decreased by a depletion rate. Each tree’s richness, i.e., the number of apples obtained from the first harvest, was randomly drawn from a Gaussian distribution with a mean of 10 and SD of 1. The depletion rate for each successive harvest of a tree was randomly drawn from a Beta distribution with parameters 14.9 and 2.0. Participants were informed that trees would vary in terms of their richness and depletion rate (i.e., some trees would be richer or poorer than others and some trees would deplete slower or faster than others), but that the trees varied in the same way across all orchards. Participants were instructed that the only factor that might change across orchards would be the time it took to travel between trees. After each block, participants could take a short break, and determine the start of the next block themselves by button press. The different blocks were distinguished by different background colors which were counterbalanced across blocks and environment types. The total number of apples harvested throughout the task was turned into payment at the end of the experiment.