Chimpanzees might be rational thinkers
Psychological research has revealed that chimpanzees can revise their beliefs when presented with new information. The study indicates that chimpanzees may be rational thinkers.
A team of psychologists have demonstrated that chimpanzees can changed their minds based on new evidence, a key feature of rational thought. The researchers presented chimpanzees in the Ngamba Island Chimpanzee Sanctuary in Uganda with two boxes, only one of which contained food. The animals received a hint indicating the presence of food in one of the boxes, and subsequently presented with even stronger evidence pointing to food in the other box. The chimpanzees frequently switched their choices in response to the new clues. This kind of flexible reasoning skills are associated with human children of about four years old.
The researchers used tightly controlled experiments and sophisticated computational modelling to ensure that the research reflected genuine reasoning by the chimpanzees rather than instinct. The researchers methodically ruled out simpler explanations such as recency bias, where the chimpanzees favoured the most recent signals, or that they reacted to the most obvious cues. The models were used to confirm that the decision-making by the chimpanzees aligned with the rational strategies in belief revision. The research challenges the traditional notion that rational thinking is a trait exclusive to humans. Chimpanzees are the closest living relatives of humans, and may be more similar to us than previously believed.
Far-reaching implications
The implications of the study are broad, and confront scientists with a reevaluation of learning, child development and artificial intelligence. The researchers intend to study the same tasks on children between two and four year old, to compare how toddlers and chimps revise their beliefs. The researchers intend to eventually extend their study to other primate species as well, building a comparative map of reasoning abilities across evolutionary branches. The research at the very least demonstrates that animals are far more capable than we assume. A paper describing the research has been published in the Science magazine.