Gender Trouble: Feminism and the Subversion of Identity (1990; second edition 1999) is a book by philosopher Judith Butler, in which Butler argues that gender is a kind of improvised performance. The work is influential in feminism, women's studies, lesbian and gay studies, and queer theory. Butler's ideas about gender came to be seen as foundational to queer theory and the advancing of dissident sexual practices during the 1990s.