372 JOURNAL OF COSMETIC SCIENCE 0.0-- -2.5 - - -5.0 ß, 25 i i I 50 75 1 O0 Hair Length in Centimeters Figure 2. Plot of the natural logarithm of the percentage of the population versus hair length (in centi- meters). suggests that 9.6 x 10-6% of the population has hair 183 cm long), or about 21 people in the USA, and that about 73 people in the USA have hair that reaches to their ankles (free-hanging length of approximately 168 + 22 cm) (see Table VI). Therefore, a lit- erature search was conducted to try to obtain an indication of the relative numbers of people known to have hair ankle-length or longer (free-hanging lengths of approxi- mately 168 + 22 cm and longer). Table VII provides a summary of persons with very long hair, and that hair has been categorized into three groups by length. Among the sources for this tabulation are the Guiness Book of World Records from 1996 and 1999 (5,6), and a long-hair website by Frank Pflonissen (7). Other sources are an internet article by Sutin Wannabovorn (8)

SCALP HAIR LENGTH 373 i -10- - -15.. -20 0 J i I 125 250 375 500 Hair Length in Centimeters Figure 3. Plot of the natural logarithm of the percentage of the population versus hair length up to currently documented hair lengths (in centimeters). about Lu Seng La, touted by Ripley's as possessor of the world's longest hair, and an internet article from the Godrej Hair Care Institute (9) about Diane Witt. The focus of the tabulated data are primarily from the past ten years rather than older data, which were purposely excluded. These longer hair lengths from the literature (183 cm [six feet] and longer) come from people from all over the world. Therefore, percentages were calculated based on the number of people at that hair length relative to the world's population of 6 billion people, assuming 4.5 billion as adults, since 75% of the world's population are age 12 and above (10) (see Table VI). As our discussion and data below show, there undoubtedly are more people in the world with hair length between t83 cm and 518 cm (between