Answer: Even if a person keeps his or her fears or disgust silent the nervous system has a way of reacting involuntarily thus making the fear or it disgust physically apparent
How does one's own body betray a person? Winston means involuntary movements a person might make from bottling up so much emotional and intellectual tension for so long. He once witnessed a man with a contorted face walking by. His expression was involuntary but Winston surely knew the man would be killed.
