How does one actually identify if they are a "man" or a "woman"? What list of criteria makes one of a certain gender?

Okay so "am I a trans person? 101". A lot of what cis people perceive as gender is best described by gender performativity theory. Basically at birth you were coded using physical sex characteristics as a guideline and a whole complex kicked into gear. You were probably praised for performing gender well and informed and shamed by others when you did not conform. This creates an external goad of social expectation that trained you how to feel about yourself. Most cis people don't appear to really question this because as long as nothing interferes with your ability to fit this model and cause social friction it's fine. Some challenge the conventions but not really identity. Gender is a thing you do rather than are under this model because it's a mass social phenomenon of culture clustered vaguely around sex characteristics. Being a Femboy for instance is something you perform. It's not a trans identity even though they might be easily mistaken for a trans woman.

But then there's a VERY different experience... And this is the rough thing to explain to cis people because it literally does not make sense. That's the hard part in this dialogue. How gender works for trans people is strictly not logical and if you experience this phenomenon you cannot logic yourself out of it no matter how hard you try... Because now we are dealing with a subconscious function. Importantly this is not a delusion. A delusion would be belief in something that doesn't exist, this is the opposite. This is intense but uncontrollable feedback about observable physical reality.

It you are trans, for whatever reason, your brain has an internalized feedback system that targets your physically held sex characteristics. Your perceptible sex characteristics make you feel things completely independent of anything external. You feel intense envy for sex characteristics you see other people have that you do not. Emulation of those characteristics make you feel incredible for literally no logical reason...it's like getting hit by a truck full of dopamine even when you acknowledge it makes no sense to feel that way. Reminders that you don't have those characteristics make you feel completely deficient. You can feel disconnected from your body and in social spaces you can feel fake or invisible, unable to express yourself. Oftentimes this friction between constant internal feedback and external pressure to conform to the opposite of that feedback causes stress which means you get stress related illnesses. Digestive issues, headaches, skin problems, harmful nervous behaviours, depression, social anxiety, escapist self medication or addiction issues... Some get metaphysical about this in the idea that there is a sort of spiritual aspect that never aligned but it's probably some kind of brain structure thing. But the idea of "being a (enter whatever here)" stems from the very consistent feedback that aggregates around a specific sexual phenotype. If you feel like your life essentially sucks because you don't have the physical characteristics that come from a masculine puberty then you can backwards engineer that feeling into the sentiement "I should be a man".

So when you face this friction between external feedback and internal feedback you have two routes to combat that stress.

Option one : You physically change the features that cause the feedback. You no longer are envious because you have the feature you want and you don't feel deficient or self conscious anymore because your physical reality has changed. The internal feedback loop is satisfied and you get that nice hit of dopamine from all forms of witnessing your physical body in action.

Option two - you remove the external feedback.

One way to not obsess over what you feel you are missing is to not be constantly reminded. Changing how everyone addresses you is part of this. When people generally call you a woman for instance what they are doing is adding up all your physical features, coming to a conclusion based on what they physically witness and spitting it back out as a physical assessment of you. Your internal feedback system is VERY AWARE of this computation happening and reverse engineers it instantly. Internally it is something like this : "This person called me 'she' because they noticed my high voice (oh how I wish my voice was lower!) and because I have boobs (fuck I wish I could just slice the damn things off) and because of my narrow shoulders (Gotta work out more) and is now creating an expectation of conforming to a cluster of social garbage and treat me like I am different from men which sucks but makes sense because I have a high voice (fuck I should talk less) and boobs (maybe if I starve myself...) " and the thought spiral continues.

So what you can do is trick the brain. You ask to be called by male forms of address and ask to be treated as culturally male and what happens is basically your mind fills in the empty room. You might not have the physical characteristics but it becomes theoretically possible to the mind that maybe those physical features aren't actually being noticed. It creates a sort of protective uncertainty. It obscures the witnessable physical assessment aspect of someone else's calculation of your sex. Even if logically it's pretty obvious what your birth sex is and you are absolutely sure someone is just gassing you up it denies that internal feedback immediate purchase. It creates room to consider - maybe my physical features aren't all that different from what I desperately wish they could be. "Man" in this usage is not just a social category. It's verbally applied medicine.

Of course the issue with option 2 strictly is that it's kind of only good at handling the feedback that comes from interacting with other people. No amount of people calling me a man is gunna help when I am in front of a mirror, or when I talk and hear my own voice or demonstrate some kind of physicality that my cis male counterparts do not have. But sometimes you get what you get and it has to be enough. Not all fully baked transitions make us perfectly indistinguishable from cis people. The process is imperfect so we ask other people to socially make up for physical shortfall.

A lot of trans people realize how important these things are once that friction is resolved. Like if you suddenly have like five different physical maladies that suddenly clear up because they were caused by stress you have normalized your entire life and you suddenly feel like going outside your house takes half the energy it used to it becomes really obvious what you're doing is working and nessisary. The experience can be a lot like quiting a very bad job that was slowly killing you.