Abstract:Humanoid robots are a form of embodied artificial intelligence (AI) that looks and acts more and more like humans. Powered by generative AI and advances in robotics, humanoid robots can speak and interact with humans rather naturally but are still easily recognizable as robots. But how will we treat humanoids when they seem indistinguishable from humans in appearance and mind? We find a tendency (called "anti-robot" speciesism) to deny such robots humanlike capabilities, driven by motivations to accord members of the human species preferential treatment. Six experiments show that robots are denied humanlike attributes, simply because they are not biological beings and because humans want to avoid feelings of cognitive dissonance when utilizing such robots for unsavory tasks. Thus, people do not rationally attribute capabilities to perfectly humanlike robots but deny them capabilities as it suits them.