Research has suggested that approach-related positive emotions are associated with greater left frontal brain activity and that withdrawal-related negative emotions are associated with greater right frontal brain activity. Different explanations for this research have been proposed. One posits that the frontal asymmetry is due to emotional valence (positivity/negativity), one posits that the frontal asymmetry is due to motivational direction (approach/withdrawal), and one posits that the frontal asymmetry is due to a combination of emotional valence and motivational direction (positive-approach/negative-withdrawal). Because research had confounded emotional valence and motivational direction (e.g., only approach-positive emotions were examined), the theoretical explanation was muddled. Solely supporting the motivational direction model, recent research has revealed that anger, an emotion with negative valence and approach motivational tendencies, is related to increased left frontal and decreased right frontal activity.