David and Tamler have their first real fight in a while over an article defending "social mixing"--distributing babies randomly across families such that no infant is genetically related to the parents who raise them.. Then they discuss a study published in Science in 2013 in which participants could earn money if they agreed to let mice be killed in a gas chamber.  Do free markets threaten our moral characters and cause us to abandon our principles? What are mechanisms behind this phenomenon when it happens? And why does David hate mice so much?Episode LinksMaus by Art Spiegelman [wikipedia.org]If babies were randomly allocated to families, would racism end? by Howard Rachlin and Melvin Frankel [aeon.co]Falk, A., & Szech, N. (2013). Morals and markets. Science, 340, 707-711. [sciencemag.org].pdf available here [gtcenter.org]