Dr Leaven's seminar is titled: 'The Referential Problem Space and Ape-Human Comparisons'. The seminar will begin at 1pm in the Old Library.
Nonverbal reference is the ability to pick out a common focus of attention between two or more interactants. For decades, cognitive scientists took the view that this capability was the product of evolutionary selection, unique to the human lineage among primates, and a developmental precursor to verbal reference. Pointing is the quintessential example of nonverbal reference. Despite sporadic reports of pointing by great apes dating back more than a century, pointing has been interpreted as a developmental index of a maturing, innate capacity for the meeting of minds in our species. With the many demonstrations of pointing by great apes in experimentally controlled conditions, it is now unambiguously clear that apes in captivity do frequently point, without any explicit training. Yet reports of pointing by wild apes are vanishingly rare. Thus, among humans' nearest living relatives, pointing emerges in some ecological contexts, but not in others, demonstrating its sensitivity to environmental input, and I will discuss the ramifications of ape pointing as a pre-adaptation for human language. Recently, some have argued that some kinds of pointing implicate mental state awareness in humans as young as 12 months of age. I will critique this perspective on methodological grounds. To my knowledge, no direct comparison of apes and humans has ever isolated evolutionary history as the explanatory factor in response differences of apes and humans, due to the presence of chronic, uncontrolled lurking variables in these direct species comparisons. These confounded variables are widely (and improperly) ignored in the contemporary literature, to the detriment of theoretical development in comparative psychology and ethology. In my view, while pointing reveals a great deal about researchers' biases and theoretical commitments, it is mute as to its psychological underpinnings.