I was just thinking; if we ever met intelligent aliens, would it be right to count them as people? I mean, OK, so they're smart enough to communicate with us, so what? They're still not human, and thus pretty much the same as any other animal, just smarter. And what is it about intelligence that should automatically give you more rights anyway? What makes humans, human? If it is intelligence, what of babies, kids, and mentally challenged adults?
Also, given the way we humans love to play God and tamper in DNA for shits and giggles, what if one day we managed to genetically engineer an Earth animal to be intelligent? Like, say, pigs. Would we have any obligation to grant smart pigs rights on par with a human? And what of their dumber counterparts? No more bacon? Although, I recon the regular, dumb pigs would be to smart pigs like chimps are to humans, which doesn't really help. A lot of people give certain protections to chimps, and it's argued that they're so similar to humans. But they're also endangered. Would smart pigs have compassion for dumb pigs because of their similarities, or nothing change, since they're so plentiful?
And what would give a robot any rights, regardless of how smart it is? In the end, it is still nothing more than a well programmed machine, even if the hypothetical technology existed to let it feel emotions.
[ I think that "personhood" is an artificial concept that most of us subconsciously redefine to our own ethical convenience. For instance, if you own a pet piglet, you are probably going to think of pigs as "persons", because your relationship with your pet is more emotionally satisfying that way. But if you're eating bacon, then you probably won't subconsciously grant pigs personhood, because in that context to do so would be emotionally distressing and dissonant. ]
Yeah, this is why I believe animals don't have souls. Any worth any given animal has, only has that value because another human put it on them. Everybody cares about their pet, but nobody cares about the stray that was put down (at least most people don't) or that gazelle that got shot. People who oppose hunting for stupid reasons seem to care about cutesie animals like deer and such, but will still gladly buy butchered cattle at a grocery store.