What makes us us? Is there a feature that unites humans as a species while setting us apart from every other animal? Tool use, perhaps, or language or consciousness? This episode is about the hunt for a biological trait that would pull us all together and why that trait is so hard to find. Even if we do discover a single attribute that is hardwired into our collective brains—like our obsession with the color red—it will always dissolve into difference in the end. Hosted and written by Sophus Helle. Sound editing by Simone Nystrup-Larsen. Edited by Andreas Lindinger Saxild. Find out more at sophushelle.com/monkeymind.