Want to sound more confident? Researchers at the University of Glasgow say your audience may be paying as much attention to your eyebrows as your words.

A study of facial movements found that subtle changes around the eyes and brows can have a significant impact on how confident a speaker appears to listeners.

The team created computer-generated speakers and varied their facial movements while keeping their spoken words and vocal tone consistent.

Participants from Western European and East Asian cultures then rated how confident the speakers appeared. Across both groups, raised eyebrows and a slow blink were consistently linked with greater confidence.

By contrast, lowered brows and narrowed eyes were associated with doubt or a lack of confidence.

Published in Proceedings of the Royal Society B, the study found that understanding spoken language requires more than just decoding words.

Successful communication relies on a range of signals including speech, vocal tone, facial expressions and physical gestures.

While previous research has shown that gestures and vocal cues influence how speech is interpreted, much less has been known about how facial movements affect perceptions of confidence.

To investigate the role of facial movements, the researchers created computer-generated speakers representing two cultural backgrounds answering questions.

The team altered only the movements around the eyes and eyebrows, leaving verbal content and vocal delivery unchanged.

Participants from both Western European and East Asian cultures watched and listened to different versions of the speakers before rating how confident their answers appeared.

Across both groups, listeners largely agreed on what confidence "looked" like.

Researchers say their findings highlight the vital role facial movements play in human communication, alongside language and gestures.

Dr Jonas Nölle, the postdoctoral researcher who led the study, said: "When interpreting speech, listeners draw on more than just the words and voice.

"By experimentally manipulating facial signals while holding verbal content constant, our study shows that even when the words and vocal cues remain the same, changing the speaker's facial movements can alter how confident or doubtful their answers appear."

Prof Rachael Jack, honorary senior research fellow at the university, and corresponding author of the study, said: "Across cultures, brow raising and eye closure were associated with increased perceived confidence, whereas brow lowering and eye tightening were associated with doubt."

The researchers say the findings build on earlier observations of facial signals in conversation by showing that such movements do not simply accompany speech but actively shape how it is understood.

So while confidence cannot be reduced to a well-timed eyebrow raise, the study suggests listeners may be picking up far more from a speaker's face than either side realises.