In one study, observers watched 12 domestic cats for six months, during which time humans worked with the animals for two hours each day.
Then, each day the cat must choose one of two images to receive a reward.
The results showed that while cats had no difficulty recognizing the animals they lived with, they only recognized humans 54.5% of the time.
This shows that cats cannot be sexed simply by looking at their faces.
Instead, they need other stimuli to distinguish between men and women, such as sounds and smells.

Can cats smell human hormones and scents?
Cats have a sense of smell that is 14 times more sensitive than humans.
Cats have 200 million olfactory senses in their noses, which allows them to detect a range of human hormones and pheromones, including pregnancy chemicals and menstruation.
Understanding whether cats can smell human pheromones and hormones is crucial for determining whether cats can recognize human sex.
Cats can smell the following scents:
I. Pregnancy hormones:
Pregnancy is a process that only women experience.
Some experts believe that cats can sense pregnancy before the expectant mother even knows it.
However, it is more likely that a cat's powerful sense of smell can detect progesterone, human chorionic gonadotropin, and estrogen produced by a woman's body.
These hormonal changes can also affect your sense of smell, which cats can detect almost immediately.
Of course, cats can sense more than just hormones.
A woman's body gets warmer during pregnancy, so cats may become more affectionate and like to rub against her for warmth.
Furthermore, cats often show great gentleness and affection towards pregnant women. This may be because they can sense the baby's faint heartbeat.
Furthermore, cats can detect changes in behavior or emotions; they can sense a pregnant woman's sadness or unhappiness.
While it's not entirely clear whether cats can distinguish between men and women based on pregnancy hormones, it's quite evident that they can recognize the unique features of pregnant women.
II. Pheromones
Pheromones are natural chemical substances secreted by the human body. They are odorless, but they stimulate social responses within the same species, much like hormones.
While some cats can detect human pheromones, they may not fully understand them.
Human pheromones have almost no effect on felines, but intelligent cats can use the signals emitted by humans to judge human feelings—whether it is happiness, sadness, or fear.
Cats use pheromones to sense human fear or adrenaline.
Therefore, some cats like to sniff people's armpits and groin. This is because there are glands located in the groin and armpits that release information about a person's age, gender, and emotions.
Women who are menstruating or have just given birth release unique pheromones that attract cats.
So when your cat sniffs your crotch or armpits, it's just trying to check your scent information to find more information about you.

Human ovulation and pregnancy are effective ways for cats to distinguish between women and men.
III. Menstrual Cycle:
Cats can detect when a woman is menstruating by smelling her scent and hormone levels.
Cats can also sense a woman's mood changes during her menstrual cycle.
However, cats have no concept of menstruation because they don't have periods; they only know that something seems to be happening inside the human uterus that they can't see.