I think this is part of why environmentalism (outside of very selfish viewpoints), and the issue of animal rights, often ends up being controversial even inside the left.

They view pretty much every other identity they have as really not important, in the grand scheme of things (well, obviously they matter, but they don't determine someone's worth), but humanity is the very last one to go. At least in part because it's something that's appealed to in order to try and win better treatment, too, but I don't think all of it is rooted in fear of other people.