This distinction between sex and gender first emerged in the 1960s in writing by psychologists such as Robert Stoller (1968). Prior to this, 'gender' referred solely to grammatical gender, that is, the classification of words as masculine or feminine, as in the French 𝑙𝑒 and 𝑙𝑎, or Spanish 𝑒𝑙 and 𝑙𝑎.
Sayfa 30 - Stoller, Robert. 1968. Sex and Gender on the Development of Masculinity and Femininity. London: Hogarth Press.