Pose, air, affectation, mannerism are comparable when they mean an adopted rather than a natural way of speaking and behaving.
Pose implies an attitude deliberately assumed in order to impress others or to call attention to oneself; it may be applied to opinions, policies, declared beliefs, and preferences as well as to manners.
Air in its more general related use may come close to demeanor (compare demeanor under BEARING ), but as compared with pose it, especially in the plural airs, definitely implies artificiality and the intent to give a false appearance, and usually also implies a vulgar pretense of breeding, of grandeur, or of superiority.
Affectation usually designates a specific trick of speech or behavior of one who obviously puts on airs or whose trick impresses others as deliberately assumed and insincere.
Mannerism designates an acquired peculiarity or eccentricity in speech or behavior; it seldom implies insincerity, but it nearly always connotes habit or potential habit. A mannerism consciously assumed becomes thereby also an affectation; what begins as an affectation may become an unconscious and habitual trick of behavior, and so a mannerism .