Apes in the Information Age: An investigation of information management by orangutans (Pongo abelii)

This dissertation explored orangutans' flexibility in information management, including both information seeking (purposive acquisition of information in relation to a goal), and information use (external application of information to a problem-solving situation). Experiments 1 and 2 investigated the types of information that orangutans could use to solve a simulated foraging task, including social and non-social cues, physically contiguous and distal cues, and cross-dimensional feature and spatial cues from a photograph. In Experiment 3, a spatial cognitive task was used to test whether orangutans could use a single array of information in multiple, strategic ways. Both Experiments 2 and 3 also contrasted orangutans' behaviour with that of human children. These three experiments demonstrated that orangutans did not exploit all information sources equally, and further, that orangutans and children attend to different aspects of information sources, even when shown identical stimuli. In addition, in Experiment 3, orangutans showed persistence in their application of previously learned information to a novel problem, whereas children flexibly changed strategies if their initial strategy failed. In the final two experiments, information seeking was investigated using a task in which information about the location of a hidden food item could be optionally gathered before a foraging choice was made. Experiment 4 tested whether orangutans searched for information only when it was necessary, and not if the location of the food was already known or could be logically inferred. In Experiment 5, the flexibility of this behaviour was tested, by varying the value of the reward, the cost associated with seeking information, and the risk of error if information was not sought. These experiments demonstrated a sophisticated level of flexibility in orangutans' information seeking behaviour. In summary, despite an impressive level of flexibility in their ability to gather information adaptively, orangutans appear to be more limited in their strategic exploitation and application of information. It is hypothesized that this limited flexibility may have contributed to the divergence in the evolution of intelligence between humans and our non-human primate relatives.