Vervet monkeys solve a multiplayer "forbidden circle game" by queuing to learn restraint

Area of Science:

• Primate behavior
• Animal cognition
• Social learning

Background:

• Coordination is essential for group success in social dilemmas.
• Nonhuman vertebrate coordination often relies on immediate responses to stimuli.
• Communication facilitates human coordination but is less understood in other species.

Purpose of the Study:

• To investigate how vervet monkeys solve an experimentally induced coordination problem.
• To understand the role of learning, hierarchy, and feedback in primate group coordination.
• To determine if communication, social learning, or policing are necessary for this coordination.

Main Methods:

• An experimental setup was created involving a food container and a "forbidden circle."
• A low-ranking female (provider) opened the container only when dominant individuals stayed outside the circle.
• Dominant individuals learned restraint sequentially, from highest to lowest rank, without human guidance.

Main Results:

• Dominant vervet monkeys learned to wait outside the "forbidden circle" in hierarchical order.
• Providers opened the food container almost instantly once all dominants showed restraint.
• Coordination was achieved through trial-and-error learning and individual feedback, not communication or social learning.

Conclusions:

• Vervet monkeys can solve complex coordination problems through individual learning and hierarchical dynamics.
• Patience and restraint, driven by individual feedback, are key mechanisms for cooperation in this species.
• This study highlights a novel form of coordination in nonhuman primates that does not rely on direct communication or social learning.