Ekman’s observation may be relevant to the British expression “keep a stiff upper lip” as a recommendation for handling stress. It might be that a “stiff” lip suppresses emotional response - as long as the lip is not quivering with fear or tension. But when the emotion that leads to stiffening the lip is more intense, and involves strong muscle tension, facial feedback may heighten emotional response.
According to the passage, stiffening the upper lip may have which of the following effects?
A. It first suppresses stress, then intensifies it.
B. It may cause fear and tension in those who see it.
C. It can damage the lip muscles.
D. It may either heighten or reduce emotional response.
