Affectation

Literary Practical psychology culture self

Etymology

From Latin "affectare" (to strive after, aspire to), a frequentative of "afficere" (to influence). The strain of striving is the point: an affectation is a quality reached for and not truly possessed, so the effort shows.

noun · /af-ek-TAY-shun/
A studied, artificial manner adopted to impress.
What it names
Put-on behavior specifically — a borrowed style worn as costume — which is sharper than the vague charge of "fakeness."
Example
The sudden mid-Atlantic accent was pure affectation; he’d grown up two towns over.
Related idea
An affectation is a specific assumed mannerism; pretension is the broader posture of claiming more importance or refinement than one has, of which affectations are the visible symptoms.