THE KEY CONCEPT: Surprise is a binary expression: there is only one way to pose surprise; unlike other facial expressions, surprise has no high or low intensity; surprise is just "on" or it is "off."
Surprise exists, it’s recognizable, and it’s easy to pose; that’s pretty much the whole story. Or, is it?
Almost all the relatively scant pictures I have of surprise are without any context or explanation – just folks looking surprised and nothing more. It’s not at all clear that the poses are spontaneous, as opposed to being posed. Can we tell the difference? (I'm even a bit suspicious of the famous Doisneau photo that starts this blog - staged or real?) It’s my personal experience that most of the situations we think might elicit surprise – people jumping out at you in the dark on your birthday, an unexpected visitor, a sudden, remarkable news event – just aren’t timed right, or are at the right level of intensity, for the face to register a surprised response someone else might be poised to notice.
It’s also the nature of surprise that it comes and goes in a flash – if it lingers on the face, it loses its meaning. In fact, I’m not sure that most of us have seen real surprise, in real life, in a way that we might have remembered or registered. And yet there is clearly universal agreement on what the expression consists of, and if the pose is correct, 90%+ agreement is easy to obtain. Surprise is binary, and it has no levels of intensity – we are either surprised, or we are not, and there is only one right way for it to look.
Let’s forgo any further philosophical discussion as to the nature of the expression of Surprise, and look at some examples of its appearance, many of which are accompanied by group-sourced user tests.
The key components of the expression of Surprise are:
- The upper lids are raised to expose the entire iris, with a fractional amount of extra eye white above.
- The eyebrows are raised straight up, creating horizontal forehead folds.
- The mouth is slackly dropped open by the lowering of the mandible, creating a smooth oval shape with no sideways or oblique stretching.
Figure 7. This emoticon seems to want to be seen as more surprised than frightened, but the mouth is far too stretched sideways to read properly.
Figure 8. Another stylized face with too much sideways mouth stretching. The eyes and brows work well. The fear component is weak, but tested 16% with my group-sourced testers.