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.