Each of us possesses multiple social identities. For example, our sex, age, race, social class, religion, political beliefs, and professions are all potential social identities. In certain contexts in which we find ourselves, that social identity may be devalued. For example, Democrats at the Republican National Convention, gays and lesbians at a custody hearing, a lone woman at a corporate board of directors meeting, black people in an all-white, southern neighborhood, or an Arab flight attendant with an American or European airline - all are at risk of having a component of their social identities devalued in the respective contexts. In response to this devaluation, they may find that their behavior or sense of self changes. Perhaps the female corporate board member speaks less persuasively than she is capable of speaking, or perhaps the Arab flight attendant chooses a different occupation, thus changing his professional identity. One need not be in an extreme situation to feel the weight of a devalued social identity. More subtle situations may also place a burden upon individuals who are in some way stigmatized. For example, when a woman takes a math test in the presence of men, she may be reminded about the stereotype of male superiority in mathematics that is alive in our culture (Spencer, Steele, and Quinn 1999; Steele and Aronson 1995). Being a woman, and thus, having a social identity that is devalued vis-à-vis mathematics ability, she may have a sense that she could be judged or treated in terms of the stereotype or that she might inadvertently confirm the stereotype. This sense can disrupt her ability to perform up to her potential, a predicament known as "stereotype threat" (Steele and Aronson 1995). In this chapter we will review the literature on stereotype threat as it relates to social identity. Specifically, we will discuss not only how people's social identity can either protect them from or create vulnerability to stereotype threat, but also how the experience of stereotype threat can influence their social identity. Thus, we will show that social identity and stereotype threat have a reciprocal relationship. Finally, we will discuss methods of protecting both social identity and achievement from the negative effects of stereotypes1.