Adult male John:
Kea John did not combine objects in the 212 actions he directed at the apparatus in the four sessions before he was given a demonstration. In the first session after the demonstration, he was highly active and performed 212 actions (mainly rummaging sand from the edge of the apparatus in 53 actions and rummaging big blocks in 99 actions), but he didn’t combine any objects. In the second session after observing a demonstrator, his 58th action was the first and correct object combination to retrieve the food. His object manipulation had some playful connotation, e.g. shortly before inserting the small block, he tossed the block into the air.
Adult male Knut:
Knut combined objects six times during the 64 actions he performed in the two sessions before being given a demonstration. Three times he combined a small block with a big one, once he put a big block on the middle part of the open tube and twice he put a small block to the lower end of the closed tube but did not insert it into the tube. In the first session after the demonstration, Knut performed 42 actions. Thus, he seemed not to be as activated as John was. But like John, he didn’t combine any objects in this session. In the second demonstration session, his 9th action was the first and correct object combination to retrieve the food.
Juvenile male Linus:
Linus combined objects nine times during the 228 actions he performed in the six sessions before demonstration. But all nine object combinations were done during the first two sessions: four times, he put the small block on the top end and once on the middle part of the closed tube, and one time each, he put the big block on the top and the lower end of both tubes. During the 133 actions of sessions 3 to 6, he didn’t combine objects anymore. In the first session after demonstration, he combined the small block with the top end of the open tube in his second action of the session (after looking into the tube). But he released it too early in order to insert it properly into the tube. He held the block to the edge of the opening once again, hesitated, and carried the block to the closed tube. There, he combined it with the top end and on the middle part of the tube for a total of 9 times, before he did so twice on the middle part of the open tube and then inserted it into the top end there, releasing the reward as the 14th object combination out of a total of 48 actions in this session. Prior to success within this session he had combined the block with the apparatus several times in a manner of tossing it down on the apparatus.