Does face shape determine personality?

Reading character from the face, physiognomy, is ancient and was popular well into the nineteenth century, when it was used to justify ranking people. It did not survive testing. Quizzes that say a square face means a leader or a round face means a warm, easy-going person are entertainment, built on the same idea in a friendlier form.

Face shape itself is mostly a matter of bone and facial fat. Those are shaped by genes, sex hormones, age and body weight, none of which maps onto a personality type in any dependable way. Two people with the same shape can be as different in temperament as any two strangers.

People do make fast judgements from faces. The best-replicated example is the halo effect: attractive strangers are rated as more sociable, competent and trustworthy at first sight. Reviews of the research find the effect across cultures, and find that it is strongest in first impressions and fades as people get to know each other.

Expression matters more than shape here. A resting face that reads tired or tense draws different guesses about personality than the same face rested and relaxed, and that part is workable through sleep, posture and how you are photographed.

Face shape is a practical styling tool. It helps choose a haircut, glasses and beard that balance the face; the face shape detector estimates yours from one photo, and the hairstyle by face shape guide gives the conventions, which are style rules of thumb rather than research. It does not say who you are, and nobody should be judged by it. For whether any shape is more attractive, see what face shape is the most attractive, and for the measurable side of faces, is facial harmony objective.