title: Scalp hair length. II. Estimating the percentages of adults in the USA and larger populations by hair length.
abstract: Scalp hair length assessments by anatomical site, previously made in Florida theme parks on adults, are related to anatomical measurements to obtain estimates of free-hanging hair lengths in centimeters. A plot of the natural logarithm of the percent population versus these hair lengths provides a straight line and an equation that permits the estimation of the numbers of persons in the USA and larger populations with hair lengths up to 183 cm (just beyond ankle-length). Data were also collected via a literature search for even longer hair lengths (ankle-length or longer) to provide an equation to estimate the numbers of persons with exceptionally long hair. A comparative plot of these two equations suggests that "normal" anagen periods may be considerably longer than current estimates in the literature.
authors.affiliation: Clarence Robbins Technical Consulting, 12425 Lake Ridge Circle, Clermont, FL 34711, USA.
authors.forename: Clarence
authors.initials: C
authors.lastname: Robbins
authors.forename: Marjorie Gene
authors.initials: MG
authors.lastname: Robbins
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006197:Hair; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States