Joshua Greene presents some tough moral questions

Alan is presented with a tough moral choice by researcher Joshua Greene of Princeton: under what circumstance might he sacrifice the life of one person to save many? Greene's research suggests the emotional weight of the decision is critical, pitting the emotional centers of the brain against the rational ones. Alan also goes into a scanner again, this time to see how he reacts to both fair and unfair offers to split a $10 prize with another contestant.