The age of puberty in boys

According to a 1994 study, boys reach puberty at around 15 years—later than girls, who usually begin menstruating around age 13.

Several signs allow for determining boys’ entry into puberty: bodily changes, such as a sudden increase in height, lengthening of the penis, development of body hair and voice change; also sexual maturity, e.g., the practice of masturbation. A survey on adolescent sexuality conducted in 1994 with over 6,000 adolescent boys and girls provides information on both types of indicators.

For eight out of ten boys, voice change occurs between 13 and 17 years. On their 15th birthday, 56% of boys have already had their voice change, according to the 1994 ACSJ survey (Analyse du Comportement Sexuel des Jeunes). Peak growth velocity (defined as an increase in height of 10 centimeters in one year) is reached at approximately the same moment. Moreover, according to this survey, nine out of ten boys masturbate for the first time between the ages of 9 and 17 years, nearly 50% of them at age 13 or 14.

In the 1994 survey, voice change appeared the most reliable indicator of puberty for boys. For girls, first period is often the most important puberty threshold. Half of girls have already had their first period at 13.1 years, whereas half of boys undergo voice change at 14.8 years. If these two developments (first period for girls and voice change for boys) are understood to define the age of puberty, then girls reach that age around 20 months earlier than boys.

Sources:

• La Rochebrochard (de) Elise, 2000, Age at puberty of girls and boys in France: measurements from a survey on adolescent sexuality, Population, An English Selection, 12 (6), pp. 51-80
• The Analyse du Comportement Sexuel des Jeunes (ACSJ) survey was conducted in 1994 by the Agence Nationale de Recherches sur le SIDA [AIDS] or ANRS with 6,175 adolescent boys and girls (3,341 boys and 2,834 girls) born between 1975 and 1978.

Contact: Elise de la Rochebrochard

Online: October 2014