Final answer:
Kinesics is the branch of linguistics that studies postures, gestures, and facial expressions as a part of human communication. It helps to understand non-verbal cues that complement spoken language and is essential in fields such as sociolinguistics and linguistic anthropology.
Step-by-step explanation:
The branch of linguistics that focuses upon postures, gestures, and facial expressions is called kinesics. This field examines how body movements and gestures carry meaning and can affect communication. Body language, including posture and facial expressions such as smiling or frowning, plays a significant role in conveying emotions and intentions in interpersonal communication. Additionally, in-person communication is enriched with these non-verbal cues, which differ from written communication that lacks such physical context.
Understanding kinesics is important not only for daily interpersonal interactions but also for public speaking and rhetoric, where it enhances the persuasiveness of the speaker. Kinesics is also considered within sociolinguistics and linguistic anthropology, subfields of linguistics that explore the various cultural, social, and emotional roles that language plays in human communication.