Abstract
When foraging for strawberries, when is the best time to move on from one location to the next to maximize your harvest? Questions like this, of patch leaving strategy, have been studied for decades in the animal literature, and more recently for human visual search. Such work has characterized a tendency toward—but not in full conformity with—optimal patch leaving times. However, little is known about individual variation in this important behavior. Here, we investigated individual variation in patch leaving strategy. In Study 1, participants searched for T-shaped targets among L-shaped distractors, in visually noisy displays. The number of targets in each display ranged from 0 to 10. We found a broad range of individual differences in strategy metrics related to patch leaving behavior, including the proportion of targets found before leaving a display, the time spent between last target found and decision to leave the display, and the time spent to find the first target. All these metrics were test-retest reliable (rs > .53, ps < .03). In Study 2, we explored the extent to which patch leaving strategy was optimal for individuals. With all displays having 10 targets, participants completed two types of blocks: 1) Enforced Completion, in which the participants needed to exhaustively find all targets in each display; 2) Free Choice, in which participants could leave each display whenever they decided to. First, we found wide variability in the proportion of targets found before leaving in free choice blocks. Second, using the enforced completion blocks, we could calculate the optimal patch leaving time separately for each participant, and results showed a wide range in deviation from the optimal leaving time. We conclude that patch leaving strategy in human visual foraging has wide individual differences and is often suboptimal.