Individual and sexual characteristics of the skull

Each skull has individual characteristics. The skull as a whole is characterized by a certain shape, size, ratio of the size of the facial skull to the braincase, the degree of development of the superciliary arches, mammillary processes, muscular tubercles, rough lines, etc. These features, as well as the size of the skull, are variable, but do not go beyond the conventional norm.

To individually characterize the shape of the skull (brain), it is customary to determine its dimensions (diameters): longitudinal, transverse, height.

• The longitudinal size - the distance from the glabella to the most protruding point of the back of the head is 167-193 mm (in men).
• The transverse dimension, corresponding to the widest part of the skull, ranges from 123 to 153 mm.
• The vertical dimension is the distance from the middle of the anterior edge of the large (occipital) foramen (basion) to the point where the sagittal suture converges with the coronal suture (bregma) - equal to 126-143 mm.

The ratio of the longitudinal size (diameter) to the transverse, multiplied by 100, is the cranial index (longitude-latitudinal index). If the cranial index is up to 74.9, the skull is called long (dolichocrania); an index of 75.0-79.9 characterizes the average size of the skull (mesocrania), and if the index is 80 or more, the skull will be wide and short (brachycrania). The shape of the head corresponds to the shape of the skull. In this regard, there are long-headed people (dolichokephaly), medium-headed (mesocephaly) and wide-headed (brachycephaly).

Looking at the skull from above, one can see the diversity of its shape: ellipsoid (with dolichocrania), ovoid (with mesocrania), spheroid (with brachycrania), etc. The capacity (volume of the cavity) of the cranial skull is also individual. In an adult, it ranges from 1000 to 2000 cm ³.

The shape and size of individual bones of the skull and the skull as a whole correspond in the process of their growth and development to the individual shape of the brain, sense organs and initial sections of the digestive and respiratory systems fixed on its bones. This is convincingly confirmed by the relief of the inner surface of the skull, reflecting the shape and development of the organs enclosed in it. For example, three cranial pits of the inner base of the skull contain the corresponding lobes of the brain. The relief of the inner surface of the skull reflects the location of the imprints of the grooves and convolutions, arterial and venous grooves, etc.

The external shape of the skull largely depends on the development of muscles that have a modeling effect on young bone tissue. The absence of one or more chewing muscles on one side of the head results in facial asymmetry and smoothing of the finger-like depressions on the inner surface of the skull. The loss of an eye is accompanied by a decrease and, subsequently, almost complete closure of the orbit. This contributes to the enlargement and smoothing of the walls of the anterior cranial fossa on the corresponding side.

Sexual differences in the human skull are insignificant. Therefore, it is sometimes difficult to distinguish a male skull from a female one. At the same time, the tuberosities (muscle attachment sites) of a male skull are usually more visible; the occipital protuberance and superciliary arches protrude more. The eye sockets are relatively large, the paranasal sinuses are more pronounced. The bones are usually somewhat thicker than those of a female skull. The longitudinal (anteroposterior) and vertical dimensions of a male skull are larger. The male skull is more capacious (by 150-200 cm ³ ) than the female one. The capacity of the male skull is approximately 1450 cm ³, and that of a female skull is 1300 cm ³. The difference can be explained by the smaller size of a female body.

The shape of the skull does not affect the mental abilities of a person. The attempts of some falsifiers of science to speak about "higher" and "lower" races based on the shape of the skull are untenable. This is evidenced by the approximately equal sizes of the skulls of representatives of different races. For example, the longitudinal size of the male skull of representatives of the Caucasoid type is on average 180.7 mm, of the Mongoloid type - 184.6 mm, of the Negroid type - 185.2 mm. According to anthropologists, the Sioux Indians have high head size indicators, and the capacity of the skull of South African blacks (1540 cm ³ ) is greater than that of many Europeans (Ya.Ya.Roginsky, M.G.Levin). V.V. Ginzburg (1963) cites figures for cranial capacity among Australians (1347 cm3 ⁾, Dutch (1382 cm3 ⁾, Swiss (1367 cm3 ⁾, Buryats (1496 cm3 ⁾, and Eskimos (1563 cm3 ⁾. Different races have both large and small cranial sizes.

Numerous studies by anthropologists have not established any grounds to believe that one race or another has a predominantly larger braincase. The somewhat smaller head sizes of Bushmen, Pygmies, etc. are explained by their small stature. Often, a decrease in head size can be the result of insufficient nutrition over the course of centuries and other unfavorable living conditions (Ya.Ya.Roginsky, M.G.Levin). Also untenable are the opinions about the allegedly different order of fusion of the cranial sutures in representatives of different races.

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