Investigating Sequence Learning in Anthropoid Primates Using Observational and Experimental Methods

Abstract

Sequence learning is a crucial aspect of human cognition, being foundational in humans' ability to learn language, develop complex tool use and in the development of cumulative culture. A recent review by Ghirlanda et al (2017) highlights that humans potentially have enhancements in these abilities beyond other animals and therefore sequence learning may be a cognitive capacity that sets us apart from other animals. Understanding how these abilities evolved and may differ in our closest living relatives, the primates, can provide novel insights into these abilities. I start by reviewing the existing literature on observational and experimental research in the anthropoid primates, by providing an overview of the observational and experimental research that has been conducted. Particular focus is paid to the areas of communication, foraging and tool use, as well as evaluating the contributions of different experimental approaches to our understanding of sequence learning abilities in primates. An observational study comparing gorillas and François’ langurs was then conducted, which used Markov Chain Analysis to identify whether these primate species differed in the sequences of behaviours they used while browse feeding. This study identified that gorillas exhibit hierarchical sequence structures in their feeding behaviours, where the langurs didn’t. An experimental study was also conducted, using a novel puzzle box experiment, aiming to provide experimental data on the manual sequence learning abilities of previously understudied species, in this case, François’ langurs and black headed spider monkeys. As the results obtained from this experiment were minimal in regard to evaluating sequence learning abilities, results are discussed in relation to improving the procedures of these kinds of experiments. Particularly when working with zoo-housed primate populations.