As an adult, you probably remember puberty — a time when your body went through a lot of changes. Professor James M. Tanner , a child development expert, was the first to identify the visible stages of puberty. Today, these stages are known as the Tanner stages or, more appropriately, sexual maturity ratings.
Puberty is the name for the time when your body goes through changes and you begin to go from being a child to an adult. Your hormone levels will change; you will develop breasts, grow taller, and start your menstrual periods. Puberty in girls usually starts between 8 and 13 years of age, however, it can also be normal for girls to start puberty before 8 or after
Jump to navigation. Breast development is caused by hormones released by the ovaries at puberty. These hormones cause fat to accumulate, causing your breasts to enlarge.