Philosophers often claim that doing philosophy makes people better thinkers. But what evidence is there for this empirical claim? This paper reviews extant evidence and presents some novel findings. We discuss standardized testing scores, review research on Philosophy for Children and critical thinking skills among college students, and present new empirical findings. On average philosophers are better at logical reasoning, more reflective, and more open-minded than non-philosophers. However, there is an absence of evidence for the claim that studying philosophy led (...) to these differences. We present some preliminary and suggestive evidence that, although some of these differences may be attributable to philosophical training, others appear to be selection effects. The key takeaway is that more data are needed. We conclude by urging philosophers and interdisciplinary collaborators to gather more data to test the claim that studying philosophy makes people better thinkers. (shrink)