New medical scans are showing the relationship between thinking, emotions and the brain. “It can show, for example, the parts of the brain that operate when we fall in love and when we have food cravings. It has even recently revealed the differences in the brains of Democrats and Republicans. But the technique also holds out the promise of answering deep questions about our most cherished human characteristics. For example, do we have an inbuilt moral sense, or do we learn what is right and wrong as we grow up? And which is stronger: emotions or logic?”