Mateusz Wozniak

When two people need to coordinate their actions — picking the same option, moving at the same time, agreeing without a plan — they can do it in two ways: talk about it, or become more predictable. But can they do both at once? And when communication is available, do people stop trying to be predictable at all?

THREE EXPERIMENTS, THREE COMMUNICATION CONDITIONS

We put pairs of participants in a joint decision task — choosing between options in real time — under three different conditions. In Experiment 1, they couldn't communicate at all. In Experiment 2, they could send minimal signals back and forth (enough to build a shared code, but not use natural language). In Experiment 3, they could talk freely.

When communication was impossible, successful pairs spontaneously started behaving more predictably — essentially making themselves easier to "read" so the partner could anticipate their moves. When full communication was available, there was no incentive to become predictable: pairs simply told each other what they were going to do. Most strikingly, the minimal communication pairs did both: they increased their predictability and invented a shared signaling system from scratch.

The takeaway: communication and action predictability are not either/or. They are flexible, complementary tools that people deploy depending on what the situation allows.

Woźniak, M. & Knoblich, G. (2022). "Communication and action predictability: two complementary strategies for successful cooperation". Royal Society Open Science, 9, 220577.

DOES COORDINATING TOGETHER MAKE US MORE GENEROUS?

A related question: does the act of coordinating change how prosocial we are? In a separate experiment, participants who made decisions in a jointly coordinated manner became more willing to act for the benefit of their partner — they were measurably more generous — compared to those who decided alone. But this generosity boost did not come with increased trust. Coordination seems to trigger a specific sense of shared fate or joint commitment, rather than simply making us like our partner more.

Chennells, M., Woźniak, M., Butterfill, S. & Michael, J. (2022). "Coordinated Decision-Making Boosts Altruistic Motivation – But Not Trust". PLoS ONE, 17(10): e0272453.