Fig. 1.

Setup for the study. In the two-tubes condition (a), the monkeys could approach the center location to peer into both tubes from the same vantage point; such information seeking was not possible in the one-tube condition (b). In both situations, the monkeys either saw the baiting event (visible baiting; side counterbalanced across subjects) or did not (hidden baiting) because Experimenter 1 (E1) first moved the occluder to block their view. Experimenter 2 (E2) filmed the trial from a farther distance.