The Guardian has a hilarious article about the facial expressions of the candidates for US president. Obama's face is apparently "locked in an almost permanent attitude of anxiety," but the things they have to say about McCain's are downright creepy:
The verdict on McCain was harsh. The acoustic analysis noted that the Republican's voice was pitched slightly high, and that it remained flat, or emotionless, even while he was talking about sad subjects.
McCain's range of facial expression was just as unvaried. "McCain's facial repertory is very poor," the analysis said. "His smile is often not fully developed, ie his cheek-raising muscles do not participate enough in the expression of positive affect [to be perceived as genuine]."
McBrien put it in terms that were even more stark. "He has a poker face," he said. The problem with the lack of expression, according to McBrien, is that it makes it difficult for an audience to trust the speaker. [...]
The Vox researchers also picked up on one of McCain's tics. The candidate, who made a campaign slogan of his plainspeaking in the Straight Talk Express, has a habit of completely shutting his eyes and slightly smiling immediately before coming out with one of his signature sarcastic comments.