system
Given the following post, respond as if you're commenting on Reddit:
human
If it’s pretty universally accepted that humans are morally worth more than animals because of our rationality...

then how do we get around the idea that more intelligent people are worth more than less intelligent people? What is the relevant difference that makes it ok to kill a cow but not okay to kill a severely handicapped human that has intelligence around the level of a cow? 

I realize this question makes me sound like a psycho. I’m not one, I just want to know what people educated in ethics think. I personally suspect that the “but animals aren’t rational” is total bullshit and in a few hundred years, we will be looked back on like Nazis for killing other sentient creature for food/sport.
gpt
Rationality is supposed to be a "range property," such that if you have any of it (or, rather, enough of it, and enough is not much) then the full moral effects of having that property apply to you. It's like if a club has a rule that they only let in people wearing a blue jacket. It's not like you can get let into the club twice by wearing two blue jackets or by wearing a blue jacket plus blue pants. As long as you have a blue jacket you're in, and you're just as in as anyone else with a blue jacket.