Pre-Crastination Emerges in a Sequential Joint Action Task.

In sequential joint actions, one co-actor performs the first step of a task (the initiator) before the second co-actor finishes the task (the finisher). Studies of sequential joint actions have revealed the initiator plans their movement to facilitate their finisher's action, consistent with the principle of "pre-crastination". Pre-crastination refers to the finding that actors choose to complete more demanding tasks earlier to decrease cognitive and/or motor load later. The present experiments examined the potential for pre-crastination in a sequential joint action task. Partners performed a task wherein an initiator passed a cube with a 3D-protuberance to a finisher so the protuberance could be inserted into a target slot. The initiator could rotate the cube all, some, or none of the way into the final orientation before passing. The results of Experiment 1 were that initiators completed more rotations when working with a partner than actors completed in the first step when working alone. Experiment 2 revealed that visual information about the finisher's task influenced the amount of rotation completed by the initiator. These findings are consistent with the notion of pre-crastination because co-actors facilitated their partner's achievement of a shared goal by doing more of the work earlier on.