The Effects of Aging on Hair–More Than Just Amount 470 the small difference found between males and females. However, since so few males and females were used in this study (6 males 8 females), even if there is a difference the sample size is so small that one cannot conclude that a difference exists between the ellipticity of the hair of males versus females. We analyzed the data differently from Trotter and Duggins by not combining the 1 month and 7 month data and we used the Wilcoxon signed rank non-parametric test for paired observations. The results, summarized in Table 8, show that the largest change occurs after 1 month when the hair is more circular in the earliest stage of infancy. The 1 month data is significantly different from all other ages, including the 7 month measurement (P 0.0001). It would also appear that another change occurs a few years later near the 5–6-year age range. Table 8. Means of the data representing the effects of age on the hair fiber ellipticity from approximately 1 month through age 10 for the same 14 Caucasian children Age Statistics Maximum/Minimum Diameter (Ellipticity) 1 month ** 1.26 2 years 1.44 3 years 1.44 4 years 1.41 5 years 1.41 6 years 1.39 7 years 1.37 8 years 1.37 9 years 1.37 10 years 1.38 7 months 1.36 Data were evaluated by the Wilcoxon signed rank test for paired observations, ** indi- cates the values that are significantly different from all others. The black lines indicate values not significantly different from each other. Knowledge gaps for hair fiber ellipticity and age: Although reported mean ellipticity values for African hair types are clearly higher than mean values for Asian and Caucasian hair, we could
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