From the current edition of Biology Letters published by the Royal Society, comes this intriguing experiment conducted by a research team at the Max Planck Institute for Evolutionary Anthropology, with the help of some obliging orangutans; here’s the abstract…

We investigated the use of water as a tool by presenting five orangutans (Pongo abelii) with an out-of-reach peanut floating inside a vertical transparent tube. All orangutans collected water from a drinker and spat it inside the tube to get access to the peanut. Subjects required an average of three mouthfuls of water to get the peanut. This solution occurred in the first trial and all subjects continued using this successful strategy in subsequent trials.

The latency to retrieve the reward drastically decreased after the first trial. Moreover, the latency between mouthfuls also decreased dramatically from the first mouthful in the first trial to any subsequent ones in the same trial or subsequent trials. Additional control conditions suggested that this response was not due to the mere presence of the tube, to the existence of water inside, or frustration at not getting the reward. The sudden acquisition of the behaviour, the timing of the actions and the differences with the control conditions make this behaviour a likely candidate for insightful problem solving.

The full paper is behind a paywall, although it’s quite possible that the contents will be covered accessibly elsewhere in more detail, but it’s nevertheless interesting to see research into the learning abilities of primates, other than chimpanzees, including the linguistic abilities of bonobos. Research of this type helps to further demonstrate that the origins and deployment of our own intelligence may not be as specialised as we have come to believe. It also raises the question of why other primates, while apparently possessing vestiges of the same cognitive abilities as ourselves, have not themselves adopted or developed more complex behaviours of their own, especially during the past few million years in which hominids have been evolving at greatly accelerated rates, for reasons that continue to elude us. (TJ)

see also: Apes Think Of The Future

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