Wilde pulled his lip in and looked funny. I knew just as plainly as though he had said it that by 'looking for Regan' he meant using the machinery of the law to look for him. --Philip Marlowe, describing how he read district attorney Taggart Wilde's lips (The Big Sleep, 1939:212)
Usage: Lip-compression is a specific version of the TENSE-MOUTH display. A sudden lip-compression may signal the onset of anger, discomfort, disliking, grief, sadness, or uncertainty.
Observation. Barely noticeable lip-clenching may signal unvoiced opposition or disagreement. Like other lip cues, in-rolling is controlled by "gut reactive" special visceral nerves.
Anatomy. At rest, the lips make gentle contact, and the teeth are slightly separated (see BLANK FACE). In lip-compression, the prime mover is orbicularis oris (both pars peripheralis and marginalis contract); the teeth may or may not occlude.
RESEARCH REPORTS: 1. In rage, "The mouth is generally closed with firmness . . ." (Darwin 1872:236). 2. Apes express anger by staring, clenching the jaws, and compressing the lips (Chevalier-Skolnikoff 1973:80). 3. In chimpanzees, a compressed-lips face "typically accompanies aggression" (Goodall 1986:123). 4. "In an aggressive mood, the [bonobo chimpanzee's] lips are compressed in a tense face with frowning eyebrows and piercing eyes" (Waal and Lanting 1997:33). 5. In the Highlands of Papua New Guinea, when men were asked to show what they would do when angry and were about to attack, "They pressed their lips together" (Ekman 1998:238).
Neuro-notes. Lip-compression is an unconscious sign controlled by the limbic system acting through emotionally responsive paleocircuits of the facial nerve (cranial VII).
Photo of New York governor, Eliot Spitzer and wife Silda at a press conference on March 10, 2008. Without acknowledging he had patronized a prostitute, Spitzer apologized for what he characterized as a "private matter." (On March 12, 2008, Spitzer resigned as governor; picture credit: unknown)