Harvard neuroscientist and philosopher Joshua Greene has brought a new dimension to the study of morality by scanning the brains of people as they struggle with philosophical dilemmas. Greene argues that humans are hardwired with a "tribal" mentality, an "us-vs.-them" perspective that leads to clashes over political and social issues like abortion, same-sex marriage and gun rights. In his book "Moral Tribes," Greene explores how we make moral decisions, whether we put individual rights above the common good, and how this explains many of the social debates between different groups and countries.
From the Archives: How We Make Moral Decisions
at 9:00 AM
(Matt Cardy/Getty Images)
Joshua Greene, neuroscientist at Harvard University's Moral Cognition Lab and author of "Moral Tribes: Emotion, Reason, and The Gap Between Us and Them"