However we would still, quite rightly, be horrified if someone suggested that we should deliberately inflict pain on these people for medical research or rear them in cramped cages and then use them as food. The reason why this would be unethical cannot simply be that they are a member of our own species. That would be arbitrary and no more logical than a racist or sexist would be in giving special treatment to their own race or gender.
The real reason that we cannot justify treating people in this way is because they would suffer pain and deprivation, through no fault of their own, and not for their own benefit. These arguments apply equally to the animals that we use for vivisection and factory farming. These practices are therefore immoral for the same reasons as if they were done to people. They should be stopped immediately.