Nonverbal behavior plays a key role in psychological counseling, which can convey rich information through body language, facial expressions and eye contact. These nonverbal signals can strengthen communication and help counselors establish better interactive relationships with clients. For example, a smile can convey friendliness and support, while a clenched fist means nervousness or anxiety. Nonverbal behavior can also express emotions and inner state. For example, changes in body posture and movements can reflect customers' emotional changes or psychological pressure.