The Influence of Unilateral and Bilateral Arm Flexion Versus Extension on Judgments: An Exploratory Case of Motor Congruence.

Two experiments were conducted to examine how activation of the motivational systems of approach and withdrawal (arm flexion vs. extension) through 2 different bodily mechanisms (right arm vs. left arm) influenced participants' evaluations of neutral Chinese ideographs. Study 1 found that unilateral flexion on the right side and unilateral extension on the left side led to more positive evaluations than unilateral flexion on the left side and unilateral extension on the right side. Using bilateral movements, Study 2 found that simultaneous performance of a right-arm flexion and a left-arm extension led to more positive evaluations than a left-arm flexion and a right-arm extension. A motor congruence hypothesis was offered to account for these findings.