Why do Europeans and Americans rarely have a single eyelid?
In our impression, it seems that European and American white men with single eyelids have not been seen. What is said here is only white people, including white women and white men. They all seem to have double eyelids. We studied biology in high school. It is said that people have dominant genes and recessive genes. Are they all dominant genes? Where did their recessive gene go? Why are their manifestations all double eyelids?
Let me explain what a single eyelid is:
Most Asians have a layer of skin creases on the inside of the upper eyelid frame, called the epidermis.
The inner condyle is a continuation of the upper eyelid folds and has a certain relationship with the height of the bridge of the nose. Obviously, the inner concretion is the so-called "single eyelid", the less obvious is the "inner double", and the one without "double eyelid" . Healthy whites without racial descent, such as Asians and Indians, have 99.9% no internal crusts. If the "purebred" whites do, it is likely to have some kind of neurological or brain disease.
White people don't have single eyelids, because they don't have Hu descent. In the west, monocular eyelids are generally considered to be Hu people. For example, Japanese and Koreans have many monocular eyelids, and often have small monocular eyelids. But as the saying goes, who cares if you have a single eyelid or a double eyelid as long as your face looks good.
Asian eyes generally have two characteristics: having epithanthic fold (also known as Mongolian Eye Fold) and missing supratarsal crease (double eyelid fold), but considering historical migration and ethnic integration, etc. Factors, this does not mean everyone, we also have many Asians with European and American eyelid characteristics and European and Americans with Asian eyelid characteristics.
As for why it appears mainly among Asians, there is a theory now that this is an evolutionary advantage
According to this theory, Asians have evolved these eyes to adapt to the tropical and arctic regions. This kind of eyelids can act as sun visors and protect against the cold, which has greatly strengthened Asians. Ability to survive in these areas.
However, this theory was not accepted by everyone, and Ohio State University researchers pointed out:
The problem with this theory is that a substantial portion of the Asian population evolved in areas outside of the tropical and arctic regions. In addition, he says epicanthic fold is not limited to Asians. The problem with this theory is that there is a large part of Asians It has evolved outside the tropics and the Arctic. Moreover, this "inner crust" is not entirely unique to Asians.
In fact, people in five places have the same characteristics as Asians, that is, epithic fold (also known as Mongolian Eye Fold) and missing supratarsal crease. The people in these five places are:
Polynesians ((Hinian), Indigenous Americans (Indian), Eastern Europeans (Eastern Europeans), Northern Europeans (Northern Europeans), Southern Africans (South Africans)
In addition to these 5 places, people in other places will also have the same eye characteristics as Asians.
The most obvious feature of Asian eyes, namely the epithic fold (inner fold), accounts for 90% of East Asians and 2% -5% of non-Asians.
Why do Europeans and Americans like Asian single eyelids?
In Asia, such as China, single-fold eyelids are generally not preferred, and double-fold eyelids are more preferred.
But if you have read some posts about the aesthetics of foreigners, you should have discovered that foreigners like Asian single eyelids.
This makes many Chinese people feel weird, just as we don't quite understand foreigners' preference for skin color.
Chinese people generally prefer skin whitening, while Europeans and Americans prefer tanning.
In the final analysis, this is probably because things are scarce and expensive, or they are called "unreachable forever."
The complexion of Europeans and Americans is inherently white, and wheat is rare, so they think it looks better. Similarly, single eyelids are extremely rare among Europeans. It is considered a unique feature of Asians. Call it the "Asian eye".