Chapter 14 481 Table 11. Caucasian children’s hair tends to be lighter in color than adults’ hair* Ages N % Brown-Black % Blond-Dark Blond % Light Blond 0-4 46 35 50 15 5-9 36 75 22 3 10-14 45 96 4 0 15-19 56 98 2 0 20-29 52 98 2 0 30+ 75 97 3 0 Total 310 *Data from anthropological study of French Canadian hair by Trotter and Dawson.19 Aging, hair luster and frizziness, considering hair color and curvature changes: The darkening effect during childhood would tend to make the hair appear more lustrous. Whether this effect for Caucasians during childhood extends to other geo-ethnic groups or not remains to be determined. On the other hand, the graying effect with age will decrease the luster of each gray hair fiber, producing a less lustrous head of hair. Nagase et al.18 reported an increase in hair fiber curvature with increasing age for Japanese females. These same scientists found that hair luster decreases with increasing curvature, which could be observed in the hair of these Japanese panelists. No other papers could be found reporting a similar finding however, this work appeared to have been done in a highly controlled experiment. Therefore this effect may occur in other populations but it needs to be examined among Caucasian and African hair type populations. Wills et al.56 found a decrease in hair greasiness and shine in post-menopausal versus pre-menopausal women. Therefore, since hair luster is multifactorial the combined effects of hair curvature and hair greasiness and any other effects with age will have to be determined simultaneously. Aging and hair frizz considering curvature and hair greasiness: Nagase et al. defined frizziness as a lack of synchronization in the