Essentialism
Etymology
From Latin "essentia," "being, essence." The intuition traces to Plato’s forms and Aristotle’s idea that each thing has an essence, but the "-ism" is modern and often critical — sharpened by opponents like the existentialists, who denied any fixed human essence, and Karl Popper, who attacked essentialism in the sciences.
noun · /ih-SEN-shuh-liz-um/
The belief that things have a fixed, underlying nature — an essence — that makes them what they are and defines what members of a category truly share.
What it names
A handle for a common and often problematic habit: assuming that groups, people, or things have a fixed inner nature, as when we speak of what someone “really is” deep down.
Example
Marketing that assumes “what women want” leans on a lazy essentialism about half the human race.
Related idea
Existentialism is its direct challenger in the human case, insisting that “existence precedes essence” — we have no fixed nature and must define ourselves through action.