Here's why:
* Horses are not humans: They have different brains, different social structures, and different ways of perceiving the world.
* They don't have language: They communicate through body language, vocalizations, and scent, not through words that define abstract concepts like "girly" and "boyish."
* Their social hierarchy is based on dominance: Horses primarily interact based on their position in the herd, not on gender stereotypes.
However, horses do recognize differences between mares and stallions:
* Physical differences: Stallions are larger and have a stronger musculature than mares.
* Hormonal differences: Stallions have higher levels of testosterone, which influences their behavior.
* Behavioral differences: Stallions tend to be more aggressive and competitive than mares, especially during breeding season.
Therefore, while horses may recognize the physical and behavioral differences between males and females, they don't have the same cultural understanding of "girly" and "boyish" that humans do.