Recent research shows that affective Motivation to Lead (a-MtL) is relevant for leadership emergence. However, women have been shown to have lower a-MtL. In order to explain this, we refer to Eagly and Wood’s Social Role Theory (2012). Our results show (1) traditional gender role beliefs (TGRB) are negatively related to women’s a-MtL. (2) Women’s lower a-MtL is partially due to a lack of same-sex role models (SSRM). (3) High awareness of gender inequality is related with higher a-MtL in women. Supporting Social Role Theory (SRT) sociocultural variables explain the sex difference in a-MtL. These variables potentially add to Chan and Drasgow’s (2001) model of antecedents to a-MtL and contribute to a more holistic theory testing of a sex-differentiated model. Theoretical and practical implications are discussed.