The white race hair common wavy hair classification and hair color from white to black (Scandinavia) has been through the different degree of brown (Greek, southern Italy), accidentally and red; at length, wavy hair and curl in medium length and microscopic. The results of the study show that the observed differences in different styles is related to differences in the characteristics of the naked eye can see on the cross section. The hair is round or nearly round, medulla is usually present; cross section of wool shape and small spiral shape hair is oval or kidney shaped, medulla, medulla dense melanin particles cover; cross section wavy and curl is oval, medulla also often exist. Aboriginal hair is wavy, cross-section is oval, like the white race, but the hair is always dark brown or black, and Thick, like black and yellow hair.
Hair refers to the maximum diameter of the rod shape or flat degree, straight hair classification index variation in 80 ~ 100; wave hair and curl variation in 60 ~ 80; the variation of woolly hair and small spiral hair under 60. That is related to the shape of the rod embedded in the skin in hair follicle in the shape of the hair, the hair follicle is straight, in the wave of hair and curls, hair follicle is slightly curved, and the wool roll and small spiral hair follicle is strongly curved or a saber shaped. In addition, there are other factors on the shape of the hair is influential, general wave see in the hair is curly hair rod because usually caused by uneven development on both sides, and curly hair, woolly hair curl and small spiral hair is lost due to its long axis on the torsion bar in the coil with torsion degree increases.
Black hair classification is dark brown or black wool curl and small spiral hair, the hair is thick and curly. As African Negroes, small spiral hair is Bushman and Hottentot unique.
Yellow hair is straight and not roll, long and thick, color is dark brown or black. Such as Chinese, American Indians, Inuit (Eskimo) is generally believed that the hair is the most hard. The melanin in the cortex and the air bubbles inside the cell, the more melanin in the cortex cells. A bubble is less, the more black hair classification color. In Asia, regardless of race hair, the distribution of the pigment is not uniform, that is in the center of the hair pigment content was slightly lower, no peripheral high, hair cuticle.