The question is, “What practical knowledge have we gained by looking at decision-making in the brain that we didn’t already have, either through introspection or behavioral studies?”
His answer is, “The best answer, I think, is that learning about the brain can help constrain our theories. We haven’t decoded the cortex or solved human nature – we’re not even close – but we can begin to narrow the space of possible theories.”
That is both an elegant and a practical answer – it claims neither too much nor too little for neuroscience, and provides a way to think about neuroscience. Ways of thinking are often much harder to grasp than what to think, where neuroscience churns out an enormous quantity of information but not necessarily an enormous range of hypotheses about people as people.
Lehrer’s answer echoes my own view of evolutionary theory, that its greatest utility is in limiting the range of possibilities when confronting the diversity and commonality of people’s behavior lives today and in the recent past. People are often aghast when I say this – but what about all the predictions, the selective forces, Darwin’s genius? But there is evolution’s strength – certain possibilities are more likely, and others are often not on the table. Combine that with the mechanistic understandings from neurobiology–the outcomes of evolutionary adaptations and present function–and suddenly the range of possibilities is constrained further.