What defining physical characteristic indicates Tanner stage III for males?

In Tanner stage III for males, the defining physical characteristic is the lengthening of the penis to about 6 cm. This stage marks a significant progression in male sexual development during puberty.

During Tanner stages, the physical changes are categorized into specific stages that describe the development of genitalia and other secondary sexual characteristics. In stage III, there is a noticeable increase in both penile length and scrotal development. The focus on the lengthening of the penis is a clear indicator of advancing puberty and sexual maturation, which distinguishes this stage from earlier stages where such changes are less pronounced.

The enlargement of the scrotum and testicular volume can also be associated with Tanner stage III, but they are not as definitive as the lengthening of the penis for this specific stage. Recognizing the key changes that define each Tanner stage helps in assessing a male's development accurately and is crucial for understanding the timeline of pubertal changes.