Javari is teaching a psychology class and tells his students, "Kenna is 31, single, outspoken, and bright. She majored in philosophy in college. As a student, Kenna was deeply concerned with discrimination and other social issues." When Javari asked his class if it was more likely that Kenna was A) a bank teller or B) a bank teller AND a feminist, most people in his class chose option B. Javari explained that their answer was incorrect because their _____________ heuristic led them astray