Facial Symmetry and Brain

Symmetry shows stability.

Scientific research at various universities around the world often shows that the average person highly appreciates a symmetrical face when viewing photos of other people. That is to say: symmetry means that the left side of the face looks the same as the right side.

Psychology

This symmetrical characteristic of the face also has a psychological background, namely: a face can appear asymmetrical when this person experiences negative stress or is trapped in a ‘devil's dilemma’. If someone feels uncomfortable in a particular situation, a difference can arise in how each hemisphere of the brain experiences the situation (or wants to deal with it). In right-handed people, you can observe that there is more tension on the left side of the face from your perspective when standing in front of him/her. (Thus, tighter facial muscles in the right side of his face, where ‘right’ here means the right side from the other person's perspective).

The left hemisphere (which controls the right side of the face) is more active. The left hemisphere is the dominant hemisphere in right-handed people. In this example, the left hemisphere is more ‘stressed’ than the right. Such a difference in muscle tension between the left and right sides of the face can also arise when someone doubts the correctness of his decision, or when someone does not fully stand behind his own choice or statement.
It can also occur when someone says something but does not fully support it himself, because both hemispheres hold a different opinion or feeling. In this instance, the right hemisphere expresses the conscious opinion of the other person, while the left hemisphere expresses that person's unconscious opinion or feeling.
Symmetry in the face indicates a well-cooperating duality of the left and right hemispheres.
People like to see a symmetrical face in others because it could indicate a ‘balanced’ personality, and thus a stable, credible partner.

Biology

In the paragraph above, I described more the psychological aspects of facial appearance. In the theory that I will describe in the next chapter, I base my arguments on biological phenomena and evolutionary processes. After all, I cannot name and elaborate on everything in this book.