Symbol learning in non-human primates: a tale of two worlds
Food preference, cognition, Neotropical primates, primates of the Old World
From the 1950s to the present day, the Great Apes of the New World (Chimpanzees, Bonobos, Orangutans, and Gorillas) have attracted the interest of behavioral scientists in many ways, including their ability to acquire language. Pioneering studies have investigated chimpanzee’s ability with sign language, and in the near past these studies have focused on symbol learning, especially by Chimpanzees and Bonobos. Our study investigates this ability in a species of a the New World primate, apart from the Great Apes (Rhesus Monkey - Macaca mulatta) and another species from the Old World (Capuchin Monkey - Sapajus apella), both known for their remarkable cognitive abilities. The experiment generally consists of an initial food preference test (M1), followed by five computerized tests (TC) aimed at relating stimuli of preferred and less preferred foods to symbols, and a final manual test with foods and symbols (M2). The project is currently in the final stage of data collection with Rhesus monkeys and early stage with Capuchin monkeys, with preliminary results in which three Rhesus monkeys have reached a criteria of 80% when relating food stimuli to symbols (and vice versa) in the computerized tasks, and one individual chose the symbol related to the most preferred food item in 70% of the trials in the final manual task.