The phenomenon of gender may be subdivided into several sub-phenomena, some of which are physical, and some of which are psychological.
First, each cell in the human body can be identified by gender. In every cell of man’s body, the genetic material is peculiarly male. In every cell of a woman’s body, each cell is clearly and exclusively female.
Second, bone structure is determined by gender. For this reason, paleoanthropologists can determine the gender of human remains given no more than a few bones from a skeleton. Given a fingerbone, an anklebone, and a rib, it is possible to discover the gender of the individual.
Third, brain structures are divided into male or female: given a brain, a neurologist can examine it and learn the gender of the individual from whom it came.
The three physical factors outlined above show us the raw data of gender: yet each culture or society will develop different structures around this common evidence.
Such concrete physical manifestations remain constant, consistent, and universal across time and space, from culture to culture, but the social constructs around them vary.
Alleged “gender reassignment” therapies and surgeries cannot change these specific gender manifestations. They are unavoidable.
Beyond physical data, there are psychological manifestations of gender.
Across all cultures, civilizations, and societies, it is a constant that men commit the majority of violent crimes - and not merely a majority, but an overwhelming majority.
Arson, assault, murder, kidnapping, and other manifestations of physical violence are clearly correlated with the male gender.
A second psychological trait of gender is a preference for certain learning styles. It is possible to offer a presentation tailored to favor one gender or the other.
For example, an algebra lesson can be designed so that it more effectively facilitates learning among girls, or among boys, or equally for both genders. An individual’s psychological style of learning is determined, in part, by her or his gender.
The task of the historian or anthropologist or sociologist is, then, to examine how different societies respond to the universal facts of gender, or how different cultures create very different institutions and traditions around the same phenomena.