Why do humans excel at ethical reasoning while AI struggles? The answer lies in the unique architecture of moral cognition.
Dr. Joshua Greene's neuroscience research at Harvard reveals that ethical decisions activate multiple, often competing brain systems⁶⁰:
- The Emotional System: Rapid, intuitive responses based on empathy and care - The Rational System: Slower, deliberative analysis of costs and benefits - The Social System: Considerations of reputation, reciprocity, and relationships
These systems often conflict. The famous "trolley problem"—would you sacrifice one person to save five?—creates neural tension between emotional (don't harm) and rational (minimize deaths) systems. This tension is a feature, not a bug. It forces us to grapple with complexity rather than defaulting to simple optimization.
AI lacks this neural architecture. It can simulate ethical reasoning by following rules, but it can't feel the weight of moral choices. It can calculate outcomes but not experience their meaning. It can optimize for defined values but not question whether those values are right.
This creates an irreplaceable role for human judgment, especially in novel situations where: - Existing ethical frameworks don't clearly apply - Multiple valid values conflict - Long-term consequences are uncertain - Stakeholder impacts are complex - Cultural contexts vary