Much evidence suggests that, from a young age, humans are able to generalize information learned about a subset of a category to the category itself. Here, we propose that—beyond simply being able to perform such generalizations—people are biased to generalize to categories, such that they routinely make spontaneous, implicit category generalizations from information that licenses such generalizations. To demonstrate the existence of this bias, we asked participants to perform a task in which category generalizations would distract from the main goal (...) of the task, leading to a characteristic pattern of errors. Specifically, participants were asked to memorize two types of novel facts: quantified facts about sets of kind members and generic facts about entire kinds. Moreover, half of the facts concerned properties that are typically generalizable to an animal kind, and half concerned properties that are typically more idiosyncratic. We predicted that—because of the hypothesized bias—participants would spontaneously generalize the quantified facts to the corresponding kinds, and would do so more frequently for the facts about generalizable properties. In turn, these generalizations would lead to a higher rate of quantified-to-generic memory errors for the generalizable properties. The results of four experiments supported this prediction. Moreover, the same generalizable-versus-idiosyncratic difference in memory errors occurred even under cognitive load, which suggests that the hypothesized bias operates unnoticed in the background, requiring few cognitive resources. In sum, this evidence suggests the presence of a powerful bias to draw generalizations about kinds. (shrink)

Recent work on testimony has raised questions about the extent to which testimony is a distinctively second-personal phenomenon and the possible epistemic significance of its second-personal aspects. However, testimony, in the sense primarily investigated in recent epistemology, is far from the only way in which we acquire knowledge from others. My goal is to distinguish knowledge acquired from testimony (learning from being told) from knowledge acquired from teaching (learning from being taught), and to investigate the similarities and differences between the (...) two with respect to the interpersonal dimensions of their structures. (shrink)

According to the theory of natural pedagogy, humans have a set of cognitive adaptations specialized for transmitting and receiving knowledge through teaching; young children can acquire generalizable knowledge from ostensive signals even in a single interaction, and adults also actively teach young children. In this article, we critically examine the theory and argue that ostensive signals do not always allow children to learn generalizable knowledge more efficiently, and that the empirical evidence provided in favor of the theory of natural pedagogy (...) does not defend the theory as presented, nor does it support a weakened version of the theory. We argue that these problems arise because the theory of natural pedagogy is grounded in a misguided assumption, namely that learning about the world and learning about people are two distinct and independent processes. If, on the other hand, we see the processes as interrelated, then we have a better explanation for the empirical evidence. (shrink)

Current debates on collective intentionality focus on the cognitive capacities, attitudes, and mental states that enable individuals to take part in joint actions. It is typically assumed that collective intentionality is a capacity which is added to other, pre-existing, capacities of an individual and is exercised in cooperative activities like carrying a table or painting a house together. We call this the additive account because it portrays collective intentionality as a capacity that an individual possesses in addition to her capacity (...) for individual intentionality. We offer an alternative view according to which the primary entity to which collective intentionality has to be ascribed is not the human individual, but a “form of life.” As a feature of a form of life, collective intentionality is something more than the specific capacity exercised by an individual when she cooperates with others. Collective intentionality transforms all the capacities of the bearers of this specific form of life. We thus call our proposal the transformative account of collective intentionality. (shrink)

Edited by Susan E. Carey, Harvard University, Cambridge, MA, and approved October 18, 2007 (received for review May 11, 2007).