j. Cosmet. sci., 54, 53-62 (January/February 2003) Scalp hair length. I. Hair length in Florida theme parks: An approximation of hair length in the United States of America CLARENCE ROBBINS and MARJORIE GENE ROBBINS, Clarence Robbins Technical Consulting, 12425 Lake Ridge Circle, Clermont, FL 3 4711. Accepted for publication May 15, 2002. Synopsis Ten hair length studies were conducted (January through May of 2001) at theme parks in central Florida, by observing and counting people with different lengths of hair with reference to specific anatomical sites. We observed 13.20% of the 24,300 males and females with hair shoulder-length or longer and 2.43% with hair down to the bottom of the shoulder blades or longer. We observed only 77 persons or 0.32% with hair waist-length or longer. Only three of these 77 persons were men. We observed 22 men with hair shoulder- length or longer or about 0.18%, among men only. Only four women, representing 0.0165% of this population, had hair reaching to the bottom of the buttocks. Hairstyles such as buns, topknots, or other styles of wearing hair bound to the head did interfere with our estimate of shorter lengths but not the longer ones (waist-length or longer). Head covers, e.g., caps, hats, scarves, etc., did not interfere with these estimates. INTRODUCTION The first part of this paper summarizes important variables affecting scalp hair length and explains why hair length is so variable. In addition, highlights from a 1972 hair length survey among 2,400 women in the USA are presented along with literature data on abnormally long hair (global) from a few different sources. The second part then summarizes data from our recent studies on hair length, taken at ten different times in Florida theme parks during the period January through May of 2001. It is believed that these data represent a good approximation of the percentages of persons in the USA with hair of the indicated lengths however, only a limited amount of evidence is available to support this conclusion. The focus of these studies was on long hair, shoulder-length or longer, for the total population studied. Therefore, the only attempts to record the hair length of men versus women were on those longer lengths. Since the focus was on longer hair, no specific attempt was made to separate the data of men versus women on the shorter-length hair into subsegments. 53

54 JOURNAL OF COSMETIC SCIENCE EXPERIMENTAL To obtain data on the percentage of persons in the US with different lengths of scalp hair, we went to four theme parks in central Florida at different dates: to Epcot three times, on January 24, March 14, and March 21 to Universal Studios on February 6 to Magic Kingdom three times, on February 9, February 28, and March 28 and to MGM Studios on February 20. Our objective was to observe and count persons with different lengths of hair. We returned two additional times in April and May to obtain the data on hairstyles and headcovers. We believe that the population at these theme parks represents a good random assort- ment of normally active adults (of all ages) across the United States. We stationed ourselves at a few different sites in these parks (generally just inside the entrance and at one or two other busy spots inside the park) and counted the total number of persons (males and females) passing by who appeared to be large young persons or adults, generally estimated to be 12 to 14 years of age or older and generally about 137 centimeters (41/2 feet) tall or taller. We observed and counted a total of 24,300 persons--- 3,000 at Epcot each time 3,000 at Universal 3,300 at Magic Kingdom on February 9 and 3,000 on February 28 and on March 28 and 3,000 at MGM Studios. The study on hairstyles was conducted on March 21 at Magic Kingdom to try to determine whether or not any hairstyles might interfere with or affect our estimates on free-hanging hair length. For this study, we classified passersby as having one of three types of hairstyles: free-hanging hair styles ponytails or braids and buns or styles bound to the scalp that might interfere with an estimate of free-hanging length. We also tried to estimate from the size of the hair bound to the head whether it was shorter than waist-length or longer than that length. The study on headcovers was conducted on May 9 at Epcot, to try to determine whether or not any headcovers might interfere with our hair length estimates. In this study, we classified four groups: no headcover caps (primarily baseball-type caps including sun visors) hats and scarves/hoods. For the hats and scarves/hoods we also tried to estimate those that interfered with our estimate of free-hanging hair length and those that did not. DISCUSSION HAIR GROWTH AND FACTORS AFFECTING SCALP HAIR LENGTH Hair length is determined by our physiology, how we cut our hair, and hair breakage. The physiological factors affecting scalp hair length are: ß genetic-related, including age ß health-related, including medications that we take Genetic control of hair length. Normally our genes determine how long our hair can grow at different stages of maturity by controlling the release of hormones (primarily testos- terone) and other chemicals that affect hair growth. Hair growth is controlled in the living part of the fiber at the base of the hair bulb well beneath the skin surface. Each hair fiber grows inside a sac called a follicle. The cells at the base of the bulb divide and