Do people attribute functions to gendered social categories? (For instance, is there something men or mothers are for?) And if so, do such attributions of function have consequences for normative judgments about what members of these social categories ought to do? In the current study, participants (N = 366) rated their agreement with 15 statements about the “true functions” of different social categories, in triads of matched masculine, feminine, and superordinate categories (e.g., fathers, mothers, and parents). Participants endorsed functional claims more for some social categories (e.g., parents) than others (e.g., kids), and their background beliefs about gender predicted variation in functional reasoning. However, across categories, participants judged that fulfilling true functions was ‘natural’ for members of the category, and they judged that category members ought to fulfill their true functions.

Folk-biological concepts are sensitive to both statistical information about feature prevalence (Hampton, 1995; Kim & Murphy, 2011; Rosch & Mervis, 1975) and teleological beliefs about function (Atran, 1995; Keil, 1994; Kelemen, Rottman, & Seston, 2013; Lombrozo & Rehder, 2012), but it is unknown how these two types of information interact to shape concepts. In three studies (N = 438) using novel animal kinds, we found that information about prevalence and teleology inform each other: People assume that common features are functional, and they assume that functional features are common. However, people use teleological information to predict the future distribution of features across the category, despite conflicting information about current prevalence. Thus, both information about prevalence and teleological beliefs serve important conceptual functions: Prevalence information encodes the current state of the category, while teleological functions provides a means of predicting future category change.

Why do beliefs that gender differences are innate (i.e., gender essentialism) sometimes lead to normative judgments about how individual people ought to be? In the current study, we propose that a missing premise linking gender essentialism and normativity rests on the common folk-biological assumption that biological features serve a biological function. When participants (N = 289) learned that a novel feature of the gender category “mothers” was common and innate, they overwhelmingly assumed that it must have served some function across human history. When they learned that it served a historical function, they assumed that it must still be beneficial in today's environment. When participants learned that the feature was beneficial, they judged that contemporary mothers ought to have it, and they were more willing to intervene to ensure that they would by constraining the choices of individual mothers. Thus, we suggest that essentialist assumptions can shape normative social judgments via the explanations people tend to generate about why certain features of natural kind categories become common to begin with. This finding articulates one manifestation of the naturalistic fallacy, with implications for policy debates about bodily autonomy and choice.

When people who are generally loyal or fair have a momentary lapse in their moral behavior, how does that impact whether we continue to perceive them as loyal or fair people––and how is this shaped by our relative valuation of loyalty and fairness? Reasoning from an error-management perspective suggests the Moral Stringency Hypothesis: Upon witnessing a moral lapse, we should be especially prone to discount category membership for our most deeply valued moral categories, given the potential costs of affiliating with people who do not reliably adhere to our core moral values. However, another line of research on conceptions of the "true self" suggests the opposite. Specifically, the True Self Hypothesis predicts that we should reliably project our most strongly held moral values onto others, even after a lapse. Across two studies (N = 720), we found consistent evidence favoring the Moral Stringency Hypothesis over the True Self Hypothesis.

Generic language (e.g., “tigers have stripes,” “girls hatemath”) is a powerful vehicle for communicating essentialistbeliefs. One way generic language likely communicates thesebeliefs is by leading children to generate kind-basedexplanations about particular properties; e.g., if a child hears“girls hate math,” he may infer that there must be an inherentcausal basis for the generalization, which in turn supportsessentialist beliefs. However, it is also possible that simplyhearing a category described with generics elicits the beliefthat the category is an appropriate kind to generalize about.On this account, even if the generic is negated (“girls don’thate math”), the generic language might nonetheless leadchildren to essentialize the category. The current studysupports the latter possibility, suggesting that even hearingnegated generics (“girls don’t hate math”) may still fostersocial essentialism.