Form follows function: An investigation into the categorical boundary of surprise

Abstract

The concept of basic emotions has been widely accepted in explaining human behavior. Yet, there is still no consensus on the distinctiveness of surprise. This study tried to compare the discreteness of surprise with that of other basic emotions in terms of their categorical distinctiveness. For this study, 27 undergraduates were recruited, and a new set of morphing sequences of different emotional expressions from two young Chinese posers was created. The results show that surprise is over-generalized to the perception of fear and that the categorical boundary is less discrete than for other emotional expression pairs. This blending is perhaps due to their confusion on both the perceptual and production levels. Additionally, a choice between external and internal validity when picking emotional expression stimuli is also discussed.