I don't know who (Abigail Thorn? Contrapoints? ...Vihart?) but someone was talking about how sometimes that's the case, that they really don't have a sense of their own gender. That they're "really" something like agender, but that it's just too much of a bother to worry about correcting people. But there are also plenty of cis people deeply invested in their own gender, who really do have toes to it and identify as that gender, but when you ask them how they know, they put it all on external things rather than internal.

That's not quite what I mean. A lot of people basically just equate sex and gender as the same thing.

But what I am talking about is demonstratable this way : ask this to a cis person pick a sex characteristic, any physically dimorphic sex characteristic. How does the existence of having that physical characteristic make you feel? Your answer cannot include how comfortable physically the ownership of that characteristic (like if we're talking something that causes physical discomfort like period cramps as example) is or an evaluation of how attractive or not to other people that characteristic is. It is not an evaluation of the individual nature of how yours compares to other people's. The rubric is just its pure existence of that characteristic in isolation. What emotional reaction do you have to possessing that characteristic?

Cis people generally return an answer that those sex characteristics don't really cause them to feel anything. They just have those things. Like they might have learned reactions to their characteristics if they don't fit a beauty standard and are made to feel deficient by other people... But otherwise on their own those things don't make them feel either happy or sad . The possession of those features have a neutral value.

They also don't seem particularly attached to their innate characteristics in theoreticals. Ask them what they think it would be like to swap to the opposite sex phenotype and they don't tend to report back any anticipated bodily sense of horror or loss. Most often they just display curiosity and a tabulation of things they would be able to suddenly experience or would change. More often than not their primary initial concern would be whether they would be attractive or not.

I think what makes most people cis is actually a lack of ability to care about which body phenotype they are riding around in. Their sex characteristics don't actually mean anything to them on their own.