Facial morphology animates the vast majority of research on face perception and anthropometry. Nearly every species learns early on that a wrinkled nose is the overture for battle, narrowed eyes are the mark of suspicion and tense lips signal the succession of pain.
Researchers from the University of British Columbia were motivated by the lack of literature exploring the influence head tilts have on perceptions of dominance from an otherwise neutral face. Five experiments later, the team published a report in the Journal Psychological Science that posits head movement can express social judgments without engaging in facial musculature.
“Tilting one’s head downward, therefore, functions as an action-unit imposter, creating the artificial appearance of a facial action unit that has a strong effect on social perception. Social judgments about faces are therefore driven not only by facial shape and musculature but also by movements in the face’s physical foundation: the head,” wrote Zachary Witkower and Jessica L. Tracy, the authors of the new study.
The researchers enlisted 1,517 subjects, over the course of five experiments, finding that people photographed with their heads tilted consistently conveyed physical dominance and intimidation. Previously conducted research suggests that there are two factors actively contributing to this impression. A downward head tilt resembles a shorter, wider face, which a meta-analysis from 2015 independently associated with dominance and aggression in male participants.
The other element that makes the head tilt inspire the appearance of “high-status” is known as “Action Unit 4” in the facial action coding system. This is a facial expression defined by eyebrows brought closer together, mimicking a V shape.
“In five studies (total N = 1,517), we found that when eye gaze was directed forward, tilting one’s head downward (compared with a neutral angle) increased perceptions of dominance, and this effect was due to the illusory appearance of lowered and V-shaped eyebrows caused by a downward head tilt.”
The impression is so subtle, that it’s just an angle away from demonstrating the opposite effect. A tilted head, in some instances, actually indicates vulnerability and or happiness. The delineating factor hinders on facial musculature engagement, or the lack thereof.