RESUMO
Ages of onset and attainment of various stages of secondary sexual characters were assessed from cross-sectional data on 1530 city schoolboys in Istanbul, Turkey. The subjects were grouped into four socio-economic classes. Ages of onset of pubic hair (11.80 years), axillary hair (13.15 years), facial hair (14.45 years) and laryngeal development (13.37 years) were relatively early in the highest socioeconomic class and agreed with recent values reported for European boys. In lower socioeconomic classes there was a relative delay of onset and attainment of the subsequent stages of secondary sexual characters. Acne was encountered in a significant proportion of the boys and increased in frequency with age. Socioeconomic level had no effect on its frequency. Gynaecomastia, unilateral in nearly half of the instances, was encountered in 7.0 per cent of the subjects. The frequency of gynaecomastia was lower in class 1 boys.
