Prior studies have stressed the role of subjective knowledge, i.e., what consumers think they know, in decision-making. For instance, Moorman (2001) finds that subjective knowledge will exert a critical impact on choice confidence. Hadar, Sood, and Fox (2013) show that consumers are more risk-seeking when their self-rated subjective knowledge is high. Other research suggests that consumers’ subjective knowledge is an important determinant of product information search (Brucks, 1985; Moorman, Diehl, Brinberg, & Kidwell, 2004; Raju, Lonial, & Mangold, 1995; Rao & Sieben, 1992) and product information processing (Alba & Hutchinson, 1987; Johnson & Russo, 1984). Moreover, the existing research suggests that this metacognitive feeling of knowing is not fixed and can be shaped by contextual factors (Alba & Hutchinson, 1987; Alba & Hutchinson, 2000; Park, Mothersbaugh, & Feick, 1994). It is critical to understand what will affect this metacognitive feeling of knowing. Drawing from social identity theory (Tajfel & Turner, 1986) and identity-based motivation (Oyserman, 2009), the present research concentrates on how social identity influences subjective knowledge and affects subsequent choice making. For instance, the comparative ignorance hypothesis suggests that comparison with more knowledgeable individuals will lead people to perceive themselves as having inferior knowledge and thus avoid an uncertain prospect (Fox & Tversky, 1995). However, an important question unanswered in previous studies is whether a person’s salient social identity per se will affect subjective knowledge and consequently influence consumer preferences. To address this research void, the current research aims to investigate whether activating one’s social identity at different breadth levels would exert an impact on subjective knowledge. Specifically, we propose that making salient an individual’s social identity at a broad versus narrow level can influence his or her subjective knowledge or perceived expertise, which in turn favors preferences for more advanced products. According to self-categorization theory (Turner, Hogg, Oakes, Reicher, & Wetherell, 1987), social identities are context-dependent and can be categorized at multiple levels of abstraction.