The present experiment examined how individuals and dyads coordinate action in a movement control task either with orwithout additional action effects. Participants pressed computer keys to keep a moving dot stimulus within a rectangleby certain key-movement mapping. Pressing a key could also cause visual, auditory, or no effect. Participants completedthe task either alone or with a partner they could neither see nor hear. The results showed that individuals had betterperformance and longer key-press than dyads. The performance of dyads was improved by auditory effects, whereasthe performance of individuals was not influenced by any additional action effect. In a subsequent STROOP-like task,participants were asked to press a computer key they used in the movement control task while being primed by eithervisual or auditory effects. The results revealed an association between auditory effects and correspondent key, whereas nosuch association was found for visual effects.