What is defined as the development of secondary sexual characteristics before the age of 9?

The development of secondary sexual characteristics before the age of 9 is specifically referred to as precocious puberty in boys. This condition is characterized by the early onset of physical changes associated with puberty, such as the development of facial hair, increased muscle mass, and voice changes.

Precocious puberty occurs when the hypothalamus matures earlier than expected, leading to an earlier than normal secretion of hormones that stimulate testicular development and testosterone production. It is important to identify this condition early, as it can have implications for growth and psychosocial development.

While the other options present concepts related to puberty, they do not accurately specify the scenario of early sexual characteristic development in boys. Delayed puberty indicates a postponement in the onset of these changes, normal puberty aligns with age-appropriate development, and pseudoprecocious puberty is related to the premature appearance of secondary sexual characteristics due to other factors without the typical hormonal changes associated with true precocious puberty. Thus, the correct identification of precocious puberty in boys emphasizes the critical developmental timeline relevant to this condition.