Analysis of the Chinese facial profile: Contours of the side face in the Tu and Zang ethnic minorities

(Press-News.org) Li Haijun and fellow researchers at Minzu University of China, in Beijing, conducted a series of geometric morphometric analyses of the contours of the side face and variations in the Tu and Zang (Tibetan) ethnic minorities from Qinghai Province, in northwestern China.

Their study, entitled "Morphometric analysis of the Chinese facial profile: Contours of the side face and variations in the Tu and Zang ethnic minorities", was published (in Chinese) in the Chinese Science Bulletin, 2014, Vol 59(16).

The team of researchers used advanced digital cameras and image processing technologies to create intricate and precise two-dimensional maps of the facial morphological features of the ethnic groups studied.

In the past, they state, traditional analysis of the human face relied on morphological classifications and linear measurements with spreading calipers and sliding calipers; this approach, however, did not lead to highly accurate representation of facial morphology.

Li and colleagues state that while some ethnic minorities in China have distinct side facial features (for example, the Zhuang and Yao groups have a more intruded sellion that can be clearly perceived with the naked eye), traditional methods of charting facial landmarks often fail to deliver measurement data that reflects those features in a precise manner.

Traditional methods of observing and measuring morphological characteristics of the human face, including the position of the sellion, the profile of the nose, the shape of the nose tip, the side profile of the upper lip, the thickness of the lip, and the protrusion of the chin, are very difficult to standardize, explain the researchers. "Subjective judgments tend to stand in the way of a more fruitful analysis as different observers reach different conclusions," they state in the study.

Geometric morphometric analysis focuses on the average shape of the facial profile, variations in different sections, classifications within the group and differences between the sexes.

In the new study, the Beijing-based scholars state they aim to contribute to research on the general characteristics and variations of the Chinese facial profile. "Studies like this," they add, "can also help accumulate first-hand data and material as part of the effort to eventually build a database on the morphological features of different ethnic groups."

Li Haijun led the group of researchers at Minzu University, which is the top academic center in China designated for ethnic minorities, with fields of study that span anthropology, ethnology, the life sciences, history and fine arts.

These researchers outlined an array of variations and common features in the two ethnic groups studied. For example, within the Tu ethnic group, variations mapped in the forehead were small, while those in the nose were relatively large. The greatest variations occurred around the lips and chin.

For the Zang ethnic group, the forehead likewise displayed small variations and the nose major variations. The section of the face around the glabella evidenced great variations.

Comparative analysis revealed that with both ethnic groups, the seventh mark collection tended to extrude more in males. The situation, however, was reversed with the trichion landmark collection, where there was an apparent intrusion among males. The section from the subnasale to the pronasale showed a more pronounced upward turn in females than in males. There was a greater intrusion with the trichion among the Zang than with the Tu.

Principal component analysis demonstrated similarities between the Tu and Zang groups.

It is possible to make a broad distinction between males and females.

The female facial profile has the following features: the nose is not as prominent as in males; an apparent arc links the forehead and nose; the forehead is relatively steep and almost on a vertical plane with the lips and chin.

In contrast, males had a more prominent nose, a flatter forehead, a more obvious sellion, and a less prominent chin.

Allometric analysis indicated that in both the Tu and the Zang ethnic groups, the seventh mark in males tended to become more intruded with increased size, and the same was true of the chin area.

Variations among females occurred most frequently in the forehead. When the size of the forehead was greater, the forehead displayed an arc-like shape; when the forehead was smaller, it had more of a vertical orientation.

Geometric morphometric analyses conducted by these researchers also suggested common morphological features in the face of the Chinese.

In their new paper, these researchers explain one of the goals of the study: "With the development of the times, communications and interactions between different ethnic groups have been increasingly frequent."

"The blending between different ethnic groups (such as through marriage)," they add, "is certain to exert influences on their morphological features, especially the minorities."

The group states: "It is therefore of great significance to record in an objective and timely manner the morphological features of the minorities."

The human face represents the greatest treasure-trove of morphological information, they explain in the study.

These scholars at Minzu University also suggest that new basic data and analytical perspectives can add to future research on the origins and blending of the Tu and Zang minority groups.

INFORMATION: Their research received funding from the National Natural Science Foundation of China (41102015) and the Projects from the Chinese Academy of Sciences(XDA05130102).

See the article: LI HaiJun, XU XiaoNa. Morphometric analysis of the Chinese facial profile：Contour of the side face and its variations in Tu and Zang ethnic minorities. Chinese Science Bulletin, 2014, 59(16): 1516-1524. http://csb.scichina.com:8080/kxtb/CN/abstract/abstract514661.shtml

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