Capuchin monkey tool use provides clues

The breadth of research in psychology is not limited to humans but reaches into questions about how all creatures learn about the world:

A new study from University of Georgia behavioral scientists reports that bearded capuchin monkeys, Sapajus libidinosus, are skilled at solving problems associated with using tools. The monkeys, like humans, use their bodies to learn about the world, according to a new paper published in the journal PLOS ONE on Feb. 27.

The scientists learned the capuchin monkeys strategically position nuts for cracking. Specifically, they find a stable position for the nut on an anvil before striking the nut with a hammer stone. As the nuts vary in size and shape, each one must be placed individually. The monkeys knock the nut on the anvil to determine if it is in a stable position before they let it go.

The research shows that haptic perception, using feel or touch to develop information about a piece of material or a situation, is part of skilled nut cracking.

"We know that humans skillfully adjust our actions to cope with variations in materials and circumstances," said Dorothy Fragaszy, lead author on the paper and chair of the Behavioral and Brain Sciences Program in the department of psychology in the UGA Franklin College of Arts and Sciences. "Though we don't often think about skill in that sense for other species, this is exactly what the monkeys demonstrated."

Like many long-term studies, this research provides tremendous value by virtue of deep insights through sustained observation. Scientists learn from years working with their subjects, and suddenly new frontiers are illuminated. Dr. Fragaszy's expertise working with Capuchin monkeys has developed over time to where real progress in behavorial science studies is in reach.