Tell me, how is a woman supposed to think, act, and dress?
You're presenting an emotional argument, not a rational one.
You keep throwing out "rational", so I'm going to try and make this as rational as possible so you can't try and claim otherwise.
We previously agreed upon the following definition of the term gender, no?
the behavioral, cultural, or psychological traits typically associated with one sex
Let us focus on the middle concept of cultural traits, as it is the one that gives clarity to the relevance of behavioral and psychological traits in regards to determining gender. While culture is a complex concept that could otherwise take an entire lifetime's worth of study to determine the meaning of, let's just take a look at the Webster definition of the term again.
a : the integrated pattern of human behavior that includes thought, speech, action, and artifacts and depends upon the human capacity for learning and transmitting knowledge to succeeding generations
b : the customary beliefs, social forms, and material traits of a racial, religious, or social group
By that definition, gender, as an offshoot of culture, is a collection of traits that define how a culture separates people of different sex. Obviously, the discussion involves western/globalized culture, so we can easily acknowledge that there are very specific traits our culture has bestowed up on the idea of being a man or a woman.
Since it is culturally accepted for clothing stores to either section themselves off by gender or even dedicate themselves to clothing for just specific genders, obviously clothing, a material trait, represents one trait that portrays a person's gender.
We also have other traits that our culture has also ascribed to our behavior and psychology that relates to gender. These include things such as vocal pitch, ways of thinking, and even the way a person walks.
I present the argument that, rationally speaking, if it looks like a duck, walks like a duck, talks like a duck, and ultimately calls itself a duck, then it is a rational, not emotional, statement to just accept it as a duck, even if it is really a goose.