In earlier studies, researchers believed that animals like monkeys, were already able to identify items in a list. In these studies, however, the researchers have argues that this behavior as a result of the animals wanting to get a form of reward.
In a recent study done by Greg Jensen and his team at Columbia University, Rhesus macaque monkeys were able to identify the order of items in a list after repeated exposure to some pairs of items taken from the list. The results were presented in an issue of Science Advances, where Jensen and his colleagues explained that the monkeys have used basic logical conclusions regarding the pairs of the items in the list, along with the assumption that it item A comes before item B and item B comes before item C in the list, then item A comes before item C.
When given rewards, the monkeys did not look at this as motivation to correctly place the ordered pairs of items. They instead used logic to estimate the order of items in the list and then afterwards used that estimation to make decisions in the experiment.
In the experiment, Jensen and his team had looked at four monkeys for each session and identified larger or smaller gulps of water delivered through tubes as reward for the monkeys. The monkeys were subjected to 600 trials to determine the order of seven items in a list. In some of the experimental sessions, the monkeys would receive a larger reward for identifying the order of items correctly and in other sessions, failure to identify the order of items correctly would result to a larger reward for the monkeys. In both conditions, however, the monkeys have shown that they have consistently learned the order of items, regardless of the reward. But the monkeys were observed to have learned the list slightly faster when given larger rewards. It was also observed that for both conditions, the monkeys have made minor errors by the end of the sessions.
Bucknell University psychologist Regina Paxton Gazes made a comment that the study made by Jensen and his colleagues can add proof to the idea that monkeys are like humans when considering pairs of items in a list that would later guide the choices they make.
