Full Idea
Quite possibly a Martian's humanoid behaviour is prompted by his having sensations somewhat unlike ours, despite his superficial behavioural similarities to us.
Gist of Idea
A Martian may exhibit human-like behaviour while having very different sensations
Source
William Lycan (Consciousness [1987], 5.4)
Book Reference
Lycan,William G.: 'Consciousness' [MIT 1995], p.57
A Reaction
I think this firmly refutes the multiple realisability objection to type-type physicalism. Mental events are individuated by their phenomenal features (known only to the user), and by their causal role (publicly available). These are separate.