 queer studies, queer studies, sexual diversity studies, or LGBT studies is the study of issues relating to sexual orientation and gender identity usually focusing on lesbian, gay, bisexual, transgender, asexual, queer, questioning, intersex people and cultures. Originally centered on LGBT history and literary theory, the field has expanded to include the academic study of issues raised in biology, sociology, anthropology, the history of science, philosophy, psychology, sexology, political science, ethics, and others fields by an examination of the identity, lives, history, and perception of queer people. Mary Ann LeFrance, the former chair of the Larry Kramer Initiative for Lesbian and Gay Studies at Yale University, says, �Now we�re asking not just what causes homosexuality, what causes heterosexuality, and why is sexuality so central in some people�s perspective?� Queer studies is not the same as queer theory, which is an analytical viewpoint within queer studies centered on literary studies and philosophy that challenges the puritatively socially constructed categories of sexual identity.