The basic form of people’s clothes during the Shang and Zhou dynasties was the upper garment and the lower garment. What is worn on the upper body is called clothing and what is worn on the lower body is called Shang. The Shang is actually an apron covering the lower body. Under the Shang, people only wear two pairs of trousers on their legs that look like sleeves today. There is no crotch or waistband. They are only connected by a belt and tied around the waist, which is called "shanyi". It got its name because at that time, the trousers only covered the shins and the area above the knees was completely naked. In order to hide this indecentness, people usually add an apron-like clothing around the waist. In order to keep the legs warm, they wear "shin coats", but they have no waistband and no crotch, and they are just two cloth tubes covering the legs. Because of this kind of clothing, if you sit on your knees, your clothes will be pressed down, but if you sit in a squat position with your legs spread forward, and the lower half is not blocked by the crotch, you can imagine what it will be like. No matter which civilization or era, it is not polite to expose your genitals in front of someone. Even after the Warring States Period, crotch pants were introduced for horseback riding, and the etiquette that has been passed down for a long time will make people think that sitting with a skip on one's legs is inappropriate. Impolite behavior.

Although clothes and skirts are used together, there is still a risk of exposing the lower body if the body moves too much. In order to avoid this situation, the ancients paid great attention to etiquette in behaviors such as walking, sitting, lying, and kneeling.

The "shank coat" can cover the calves, but it is still relatively easy to expose, so the ancients required that even when working ("Book of Rites" has "No need to wear clothes when working, no need to wear clothes in summer") ” argument), nor can you lift your skirt.

Pants did not appear until after the Warring States period when improvements were made, which was considered "poor". It not only reaches the crotch but also connects to the waist, and a gear is connected between the two strands. The crotch is not sewn and tied with a belt, thus forming open-style trousers. This is the original invention of crotch pants. However, people in the upper class don't like it. Such clothes are only worn by the working people at the bottom of society.

Furthermore, the ancients knelt down, and the most respectful thing was to kneel straight up. For example, when speaking to the venerable or toasting, they usually sat on their own feet, but sitting with a skip in their hands was He spread his legs like a dustpan and made it. When Zhuangzi's wife died, he would sit on the drum pot with a dustpan while singing and was scolded by Hui Shi. Personally, the reasons why I consider it rude are that I don't follow the etiquette rules, it doesn't look good (looks too arrogant?), and it seems too casual to talk to others.

During the Han Dynasty, the nobles invented the "shanyi" made of silk, which was also known as "dandy" (dandy with trousers, and dude refers to the children of nobles or wealthy families), which became popular in the upper class. . But this thing is still not good at protecting privacy, so men in the Han Dynasty had to kneel when eating (chairs had not been invented at that time).

At the end of the Eastern Han Dynasty, a new type of trousers became popular. They were mainly spacious, and the two trouser legs were made particularly fat, hence the name "big mouth trousers", and the matching tight tops were called pleats. The combination of the two is called "pleat", and its origin is not unrelated to Hufu. By the end of the Han Dynasty, it had become a variety of casual and regular clothing for both men and women.