Nobody said that humans implement utility functions. Since I already said this, all I can do is say it again: Values, and utility functions, are both models we construct to explain why we do what we do. Whether or not any mechanism inside your brain does computations homomorphic to utility computations is irrelevant. [New edit uses different wording.]
Saying that humans don’t implement utility functions is like saying that the ocean doesn’t simulate fluid flow, or that a satellite doesn’t compute a trajectory.
You could equally well analyze the utils and the fuzzies, and find subcategories of those, and say they are not exchangable.
The task of modeling a utility function is the task of finding how these different things are exchangeable. We know they are exchangable, because people have preferences between situations. They eventually do one thing or the other.
Nobody said that humans implement utility functions. Since I already said this, all I can do is say it again: Values, and utility functions, are both models we construct to explain why we do what we do. Whether or not any mechanism inside your brain does computations homomorphic to utility computations is irrelevant. [New edit uses different wording.]
Saying that humans don’t implement utility functions is like saying that the ocean doesn’t simulate fluid flow, or that a satellite doesn’t compute a trajectory.
It’s more like saying a pane of glass doesn’t simulate fluid flow, or an electron doesn’t compute a trajectory.
Which would be way off!
Does it flow, or simulate a flow?
Neither.
So how would you define rationality? What are you trying to do, when you’re trying to behave rationally?
Indeed, and a model which treats fuzzies and utils as exchangeable is a poor one.
You could equally well analyze the utils and the fuzzies, and find subcategories of those, and say they are not exchangable.
The task of modeling a utility function is the task of finding how these different things are exchangeable. We know they are exchangable, because people have preferences between situations. They eventually do one thing or the other.