Pubertal changes in boys and girls in Newcastle upon Tyne.

669 boys and 753 girls born in 1962 and living at home were observed at approximately half-yearly intervals from 9 to 17 years of age. Mean ages of reaching various developmental stages were calculated for voice change and facial hair in boys, menarche and breast development in girls, and for axillary hair in both sexes. Peak height velocity and age at which it occurred were also calculated for both sexes. Means were generally in good agreement with those found about 15 years previously in the Harpenden Growth Study. Most pubertal changes in the present study showed gradients by social class; in boys, development was later in those with fathers in unskilled manual occupations, whereas in girls the greatest differences, where found, were between those with fathers in non-manual occupations and the remainder.