Here’s an interesting study: psychologists at the University of York wanted to investigate first impressions. They had people rate 1000 images of faces on different social traits (this person looks more approachable, that one looks less dominant) and also mapped “65 physical attributes, such as eyebrow width, mouth area, and cheekbone position” … even head angle!
Then, with some statistical analysis, they were able to show how different physical traits influence our first impressions. We obviously use physical cues to determine how attractive someone is, but according to the study those same cues influence what we think about their personalities.
These cartoon faces are based on the study - the researchers took their objective measurements of various facial features and optimized them for certain traits. Obviously we can’t control a lot about our faces, but the study does suggest that if you want to appear more approachable, smiling really big and tilting your head to the side (at a 10.21 degree angle to be precise) might help.
Source: Richard J. W. Vernon, Clare A. M. Sutherland, Andrew W. Young, and Tom Hartley, Department of Psychology, University of York