Navone on Eyebrows

Navone's got a good post on eyebrows

here's some of the gems:

Animation tip: have your brow animation precede any head or body movement. Otherwise the brow action will be lost in the movement and the audience will miss it. This technique also helps to make the character look like he's thinking before he's acting.

And here are some interesting behavioral facts about brows:

* As the pitch of the voice raises the brows go up
* As the pitch of the voice lowers, the brows likewise drop
* When asking a question where the answer is already known, the brows raise
* When asking a question where the answer is truly unknown, the brows lower
* Spontaneous facial expressions (surprise, fear, pain, etc.) tend to be symmetrical, where as expressions we choose to make (curiosity, suspicion, contempt, etc.) can be more asymmetrical.

These are just trends, not rules