"Is it true that men of certain races have bigger penises?"

This is one of the most frequently asked questions I've encountered in all of my years teaching college level Human Sexuality courses. Unfortunately, however, it's a very difficult question to answer with any degree of certainty. As discussed in previous articles, studies of penis size are typically fraught with problems. For one thing, different methods of data collection can lead to wildly different conclusions (e.g., who is doing the measuring: the participant or a trained researcher?). Not only that, but there is likely a big selection effect in studies about such a sensitive topic (i.e., perhaps only men who are more comfortable with their penis size will opt to participate). As a result, we need to take most studies in this area with a grain of salt.

That said, the existing data suggests that there may indeed be some race-based differences in penis size, and those differences would appear to be consistent with popular stereotypes [1]. Specifically, several studies have found that men of African decent tend to report the longest penises, while those of East Asian decent typically report the shortest penises. Men in Europe, North America, and Australia tend to fall somewhere in the middle. Check out the map below for a better sense of the relative size difference across countries; however, keep in mind that the numbers on this map represent averages and that there is a lot of within-race variability.