Joint Action

This game puts two players on the same map with a single shared goal — but no way to talk to each other. Can two people, watching only each other's actions, spontaneously divide up a task and coordinate almost wordlessly?

The Game

Two participants each control their own avatar on a shared 11×11 grid, divided into four quadrants connected through a central hub. Their joint mission: collect an exact number of red and blue gems scattered across the map, working together within a time limit. Communication is not allowed — players can only see the map and infer their partner's intentions by watching where they move and which gems they pick up.

Across trials, we manipulate how gem colors are spatially distributed: in some maps, colors are spread evenly across all four quadrants; in others, one quadrant contains gems of only a single color, opening the door to strategies where each player specializes — one by color, one by location.

Research Questions

• When faced with a shared task and no communication, do pairs spontaneously divide labor — and if so, how (by color? by location)?
• Does the structure of the environment (evenly vs. unevenly distributed resources) shape which coordination strategy emerges?
• Do these strategies affect how equitably effort ends up being shared, and how efficiently the pair performs?
• How much does experience with one environment carry over and shape strategy in a new one?

This project extends my work on decision-making from individual choices toward joint action and multi-agent coordination — asking how two people's separate decisions become intertwined, moment to moment, into a shared strategy. Data collection and analysis are currently ongoing, with a second experiment further examining how the cost of monitoring a partner's progress shapes coordination.