[They] are just that: human ideas.

Okay, human sexual dimorphism. No matter which time and culture you look at, there are two sexes. If we ever venture out into space and live on different planets, there will still only be humans that produce eggs and humans that produce sperm. You can look in a microscope and verify which one is which with any given cell. You can dig up a skeleton and tell if it’s male or female. A simple blood panel will tell you which sex you’re looking at. Sex is unchanging and verifiable.

How about gender roles? Well, it turns out any given culture tends to have differing ideas about what things are appropriate for each sex depending on which time you catch them. And that just with one culture. Differing cultures can (and do) have drastically differing ideas about this. If we go live in outer spaces, who even knows what roles we’ll relegate to which sex? There’s no quantitative test to ascertain what these roles might be. The expectations you put on the sexes are changing and completely unverifiable.

So, idk, which one seems like an objective fact and which seems like a human idea?