If you and I agree that a furrowed brow indicates anger in a given context, and I furrow my brow, I am efficiently sharing information with you. My movement itself does not carry anger to you
Barrett argues that the brow’s expressive movement functions not as a universal emotional signal but as a socially constructed, collectively agreed-upon communicative act requiring shared conceptual frameworks.
, How Emotions Are Made: The Secret Life of the Brain, 2017thesis