A frown is a facial expression characterized by a downward turning of the corners of the mouth and often involves furrowing of the brow. It typically indicates feelings of sadness, disapproval, or concern. Frowning can occur in response to negative emotions or situations, and it is a common non-verbal way for people to communicate their feelings. Frowning is often contrasted with smiling, which expresses happiness or approval. The act of frowning can also be involuntary, as it may happen when someone is deep in thought or concentrating. In psychology, frowning is studied as part of emotional expression and can be linked to various mental states and social interactions.