What do monkeys know about others' knowledge?

Area of Science:

• Cognitive Science
• Comparative Psychology
• Primate Behavior

Background:

• Comparative psychologists propose primates represent others' knowledge states.
• Evidence suggests primates expect others to track unseen objects.
• Limited research explores if primates attribute sophisticated object knowledge to others.

Purpose of the Study:

• Investigate if primates attribute knowledge acquired through mental object transformation.
• Test if rhesus macaques expect a human demonstrator to solve a rotational displacement task.
• Determine if primates understand dynamic updating of unseen object representations.

Main Methods:

• Monkeys observed a human hide fruit in one of two boxes.
• Both monkey and demonstrator viewed boxes rotating 180°.
• Experiment 2 controlled for simple location expectation by having the demonstrator miss the rotation.

Main Results:

• Monkeys looked longer when the demonstrator reached into the empty box post-rotation.
• This indicates monkeys expected the demonstrator to track the fruit's location.
• When the demonstrator missed the rotation, monkeys showed no location preference.

Conclusions:

• Results support the interpretation that rhesus macaques attribute dynamic object representation updating to others.
• Primates may possess more sophisticated social cognition than previously demonstrated.
• This study advances understanding of non-human primate theory of mind and social learning.