Performativity
The idea that language does not just reflect realities but also creates them. (See: Hyperstition.)
The idea can be applied to many fields, but has particular relevance to gender theory and identity, in that gender itself is constructed through speech and other forms of communication rather than a preexisting reality. Actions, behaviors and gestures are the result of one's identity and a source that contributes to the formation of their identity. This particular theory was proposed by philosopher and gender theorist Judith Butler.
Perhaps to be contrasted by map-territory relation.