The joint Simon effect: a review and theoretical integration

Abstract

The social or joint Simon effect has been developed to investigate how and to what extent people mentally represent their own and other persons' action/task and how these cognitive representations influence an individual's own behavior when interacting with another person. Here, we provide a review of the available evidence and theoretical frameworks. Based on this review, we suggest a comprehensive theory that integrates aspects of earlier approaches-the Referential Coding Account. This account provides an alternative to the social interpretation of the (joint) go-nogo Simon effect (aka the social Simon effect) and is able to integrate seemingly opposite findings on joint action.

Keywords: joint Simon effect; joint action; referential coding; review; social cognition; stimulus-response compatibility.

Figure 1

Referential coding in the go-nogo versions of the Simon task. The figure shows tasks in which the agent operates the left response key. In the Solo version, a left keypress produces numerous action effects (i.e., something manual and fast, with an index finger moving, something human on the left that comes with a clicking sound, etc.) and can thus be coded in many ways; i.e., be represented by any of these and other action effects. In the Joint condition, the same action effects are produced and could be used for referential coding, but most of them are shared by the other, alternative event. With one exception: the location. Discriminating between the two action events thus requires emphasizing (attending to, weighting more strongly) the corresponding (response) location. This makes the left keypress to be represented mainly as “left.” Any event sharing that feature (such as a target stimulus on the left side) will thus activate the corresponding action more strongly in the Joint than in the Solo task-the Joint Simon effect.