One of the most intriguing problems in pediatrics is the reason for the progressive secular decline in the age of puberty. In the exploration of various potentially causative environmental factors, studies using standard methods in different cultures have become attractive as ways to resolving this problem, as well as casting new light on other matters such as relationships between early and late development and body build and the prevalence of reported menstrual symptoms which appears as one of the major causes of loss of efficiency in working American females.
Of the group of 111 girls which provides the data for this report, 77 formed part of a sample taken by us in 1955 from a total of 2,934 boys and girls in the first two grades (sixth and seventh) of the Florence, Italy, junior high schools. Every 15th child was chosen from the alphabetical lists and thus 195
YOUNG HB, ZOLI A, GALLAGHER JR. Events of Puberty in 111 Florentine Girls. Am J Dis Child. 1963;106(6):568-577. doi:10.1001/archpedi.1963.02080050570007