NOSE WRINKLE
The skin across the bridge of the nose creases, the nostrils may rise slightly, and the upper lip may lift.
Disgust. Triggered by smell, taste, sight, or — most usefully for behaviour reading — an idea.
Disgust is one of the basic universal expressions. It appears when someone hears an idea they find distasteful, even if they verbally agree. A useful predictor of unstated objection. Often brief — under half a second.
A reaction to an actual bad smell.
