Why do token materialists think different organisms could feel pain through different physical processes?

In the philosophy of mind, the view that mental states are identical to physical states faces a significant challenge: the "type-identity" theory, which suggests that every mental state (like pain) must correspond to the exact same type of physical state (such as a specific firing of human neurons) in all beings.1

Token materialists avoid this rigid requirement by distinguishing between types and tokens of mental phenomena. They argue that while every mental phenomenon is identical to some physical phenomenon, it does not have to be the same type of physical phenomenon in every instance.1

This perspective allows for the possibility of "multiple realizability," where different organisms—such as humans, animals, or even hypothetical extraterrestrials—could experience the same mental state (pain) through entirely different physical or neurophysiological processes. By focusing on token-identity, materialists can maintain that mental states are physical without being forced to claim that all creatures must share the same biological hardware to feel pain.12