Here's my theory. The emotional state of other people is of enormous importance to us. When we encounter someone, we instinctively attempt to read their state of mind from their face: are they unfriendly or friendly, annoyed or content, sad or cheerful? This works great when the face is portraying one of the cardinal emotions – Anger, Sadness, Joy, Surprise, Disgust, and Fear – but not so well if the face is so relaxed that all the usual cues are slight and ambiguous.
KEY POINTS about NEUTRAL FACES:
It is more difficult to get unanimity on neutral faces – faces without any expression - than any of the six cardinal expressions.
On average, one-quarter to one-third of viewers perceive realistic faces with no expression as sad.
Stylized faces can be more successful at portraying a neutral expression than realistic faces because so many details which are liable to various interpretations are missing. Only the essentials are included.
Neutral faces are the result of a person NOT feeling a dominant emotion - they are instead experiencing a stable, everyday mental state. It’s what we usually see, day in and day out, on the faces of people walking past us in the street, sitting on the subway, or drinking a cup of coffee in a café.
The problem is that we can’t turn off our expression-detecting radar, and given the slightest excuse, we will read into these neutral faces a feeling that quite often is not really there.
Figure 2. Here’s a classic example. This IS a neutral face, but the gentleman's enormous, showy eyebrows, his pronounced naso-labial fold (runs down the cheek) and naturally down-turned mouth, give viewers considerable room to perceive emotion. 90% of the testers agreed his wasn’t neutral, but their alternative answers were all over the map. Such disagreement is common with neutral faces.
Figure 3. This test is more typical than Figure 2. The actress was asked to assume a blank face. Sadness is by far the most common misreading of relaxed faces, as shown here. What features make her look sad - perhaps her shadowed eyes? Or, are many people simply predisposed to see sadness in an otherwise inexpressive face?
Although I have never achieved agreement much over 60% with a realistic Neutral face (and that’s hard to achieve), it is quite possible with stylized faces to get a much stronger agreement. The drastically reduced amount of detail, and the absence of creasing, shadowing, and bulging (all of which can trigger a perception of expression) makes it much easier to “tune out” the ambiguous cues that lead to disagreement when viewing neutral, realistic faces.
We’ve all heard “expert” interpreters wax eloquent with deep psychological interpretations of portraits, claiming an authority to read volumes of information in a deadpan face where no two people might agree. The art historian Laura Cumming was so insistent on the validity of her narratives of what various self-portraits expressed, that I finally abandoned her book A Face to the World: On Self-Portraits. Here is her over-the-top claim for the self portrait of German artist, Anton Mengs:
Figure 4. “But the eyes are red with exhaustion, the jaw hangs, the mouth is open and faltering as if trying to form a phrase. The artist stammers; whatever he really is cannot be summoned. Here he is in this false position, turning himself inside out to coincide with some sort of public image. But Mengs seems to doubt not just the imposture but himself as well, as if he knew he could never live up to expectations.”
- The eyebrows are level and not elevated;
- The upper eyelid grazes the upper rim of iris;
- The line between the lips is horizontally aligned with the corners of the mouth.