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Lecture Notes

Hormone levels increase at the age of nine or ten as a child approaches puberty causing the development of secondary sex characteristics including the onset of menstruation and ejaculation. For girls, this occurs between seven and fourteen years of age and includes a growth spurt, breast development, growth of pubic and underarm hair, the onset of vaginal mucus secretions and menstruation.

Early puberty, known as precocious puberty, occurs in girls as young 8 years old. It is seen in approximately 8% of Whilte girls and 35% of Black girls in the United States. The potential factors causing this early onset includes weight gain, a protein called leptin, hormones in meat and milk, and exposure to certain pesticide that act as hormone disruptors. However, no one knows for sure. The psychological effects of premature sexual development is that young girls look older and so they are pressured to act older. This may influence early dating and possible progression toward early initiation of sexual intercourse. But they are mentally unprepared for the outcomes and responsibilities of sexual behavior.

Generally, boy lag about 2-3 year behind girls in pubertal development. The average age of puberty is 11 ½ to 12 years. Physical changes are a growth spurt and muscle mass growth. It also includes voice deepening, facial, underarm, pubic area hair growth, and the enlargement of the penis, the testicles and the ability to ejaculate.

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