Albert Mehrabian is a psychologist known for his work on the importance of nonverbal communication, particularly in understanding how feelings and attitudes are expressed. His research led to the development of the 7-38-55 rule, which suggests that when people communicate, only 7% of meaning is derived from spoken words, while 38% comes from tone of voice and 55% from body language. This insight has significant implications for interpreting nonverbal cues, understanding the interplay between verbal and nonverbal communication, and managing speech anxiety.