Video_S2-Twotubes-Hidden

Video S2: Two tubes condition—Hidden baiting. In the experimental demonstration, E1 lifts up the two tubes, taps them against each other to show they are empty, and then places them in the v-shaped configuration on the ground in front of the occluder. Before baiting the tubes, she moves the occluder in front of the tubes (from the monkey’s perspective). She then picks up a fake fruit with her left hand (hand counterbalanced across monkeys) and moved it down; the monkey’s view of the baiting event is then blocked by the occluder. She then picks up the occluder and walks away so that the monkey can approach; in the real study she moved behind the camera person (E2). In the example response clip, the monkey approaches and looks in the center opening of the tubes; in this example, the monkey visibly checks both tubes from this center position. Note that orientation of video switches: in the demonstration it shows the monkey’s perspective, whereas in the example test clip E2 is behind E1 while she does the demonstration.