Physical Changes Associated With Adolescence in Boys

Examination of US Puberty-Timing Data from 1940 to 1994 for Secular Trends: Panel Findings

“…Comparison of the age of PH2 onset for white boys between the earlier studies 17,61,69 and NHANES III (1988 -1994) 6,7,45 suggests that the mean or median age for pubic hair development onset has declined by ϳ0.2 to 0.5 years; however, Foster et al 61 reported a higher PH2 mean age for white boys than previous or subsequent studies (from the 1940s to 1950s and the 1988 -1994 NHANES III; Table 5), suggesting that pubic hair staging is not a reliable marker. Sun et al 65 reported that PH3 and PH4 were earlier for white boys in NHANES III compared with NHES III.…”

“…For example, the earliest data on the age of puberty in US boys were from small, mostly high-SES white populations. 14,17,69 The first boys' data representative of the US population were collected from 1963 to 1970 in NHES III. 70 The earliest ages included in NHES III or HHANES data are not optimal for estimating the mean ages of the onset (eg, 14.5% of 10-year-old Mexican American boys in HHANES already had begun genital development) com- pared with the earliest ages assessed in the Bogalusa and NHANES III studies.…”

“…Comparison of the timing of genital development for white boys between the studies conducted in the 1940s to 1970s 14,17,61,69 and the 1980s to 1990s 6,7,45 suggests that the mean or median age of G2 declined by 1 to 2 years (Table 5). For the age of G3, the difference is less dramatic but is also earlier in 1988 -1994.…”

“…Mean ages for PH4 and PH5 exhibit variability among studies, even among those performed in the same decade. Looking at the percentages of 12-year-old white boys in PH2 or higher between NHES III and NHANES III data, similar percentages (73.5% for NHES III; 71.5% for NHANES III) were reported, suggesting no change in the timing of progression of pubic hair development overall between 1966 -1970 and 1988 -1994. For white boys' data, comparisons of the duration of male puberty are limited to the studies of Reynolds and Wines, 69 Lee,17 and NHANES III, from which the pubertal interval for white boys can be calculated as ϳ4.6 years (1940s), ϳ3.4 years (1960s/1970s), and ϳ5.5 to 5.6 years (1980s/990s). Excluding the study by Lee, which found a shorter pubertal interval than the earlier study (perhaps reflecting pubertal measure variability issues), the other studies suggest that the pubertal interval has increased between the 1940s and the 1990s.…”

Assessment of Growth and Maturation during Adolescence

“…The most widely accepted assessment scale is described as the Tan ner Scale or the Tanner Staging Technique. It was devel oped by Tanner [9] and was based on the work of Rey nolds and Wines [10] and Nicholson and Harley [11], Tanner [9] divided the processes of breast development in girls, genitalia development in boys, and pubic hair devel opment in both sexes into five stages and axillary hair development in both sexes into three stages. The usual ter minology is to describe breast development in stages BI BS, genitalia development in stages G1-G5, pubic hair development in stages PH1-PH5 and axillary hair devel opment in stages A 1-A3.…”