Determination of the mental age of orangutans compared to humans

Objective: The main objective of this work is to compare the mental development of orangutans with the mental development of human children in order to find appropriate activities that allow a better development of these animals in captivity. Methodology: To accomplish this, we considered activities proposed by four authors (Papalia, Piaget, Portage, and Freud) that can be correlated to different stages (ages) of human child development. The activities were applied to two orangutans that live in the Sao Paulo Zoo. Results: Based on their behavior, it was possible to calculate the average mental age of each animal compared to that of a human child. Conclusion: Using the result of this study one can develop activities to stimulate cognition, sociability, and motor coordination according to the mental age presented, as usually done with human children.