it may seem natural to ask: “How exactly is the project of experimental philosophy, thus defined, distinct from that of social psychology?” The best answer is that this is precisely the sort of question that experimental philosophers want to reject. A guiding theme of the experimental philosophy movement is that it is not helpful to maintain a rigid separation between the disciplines of philosophy and psychology. Experimental philosophers explore issues that are central to traditional philosophical concerns, but in practice many papers in experimental philosophy are coauthored with psychologists, and many have been published in psychology journals. Much as in psycholinguistics or experimental economics, what we see emerging is an interdisciplinary research program in which philosophers and psychologists work closely together by combining the tools once thought native to each field in the pursuit of questions of renewed interest to both disciplines. (For contrasting perspectives on the more general nature of experimental philosophy, see Alexander et al. 2009, Knobe & Nichols 2008, Nadelhoffer & Nahmias 2007, Sosa 2007.)
Perhaps the best way to become acquainted with the field of experimental philosophy is to look in detail at the actual research findings. To illustrate the substantive contributions of experimental philosophy, this review focuses on research programs in four specific domains. Within each domain, recent work has involved a complex collaboration among philosophers and psychologists, and the resulting research draws on insights from both disciplines. Though research in each of the domains is concerned with a distinct substantive question, our hope is that, together, they will serve to illustrate the general approach that has been characteristic of the experimental philosophy movement as a whole.