Interpersonal communication also differs from such events as formal group presentations and public speeches because it’s dynamic—that is, constantly changing. When you interact with others, your communication and everything that influences it—your perceptions, thoughts, feelings, and emotions—are continually shifting.

For this reason, no two moments within the same interaction will ever be identical. Imagine that your friend starts a conversation by sharing exciting news about receiving a job offer. The encounter starts on a positive note but changes when you learn that it’s the same job you wanted—making you happy for your friend but also sad and envious that you didn’t get it.

Moreover, because interpersonal communication is dynamic, no two interactions with the same person will ever be identical. So though you were comfortable talking with your father last Sunday on the phone, things may feel more awkward the next time you talk because he seems preoccupied.