Why do guys who look to be in Tanner stage 5 still grow?

Last updated on March 10, 2022

Question:

Is it normal for a boy like me, with a bone age of 14-15 years old, probably about 14.7, to be in tanner 4, or is it because of my ethnicity that I’m just naturally hairier and my pubic hair is thicker and distribution is different? I noticed that all of my friends, who are hairy just like me, are supposedly in Tanner 5 just by their pubic hair distribution, but they still grew 3 inches last year. I’m one of the youngest in my class.

Answer:

Bone age is meant to indicate that the average boy of that age has a similar bone structure. Therefore, despite your current physical age, your bones are similar to the average 14 to 15-year-old. See What is the difference between bone age and a Tanner Stage? for more detailed information. Basically, a bone age of 14.7 puts you in stage 4.

One of the reasons the Tanner Stage Calculator for Boys asks a variety of questions is that one external marker doesn’t precisely tell you where a person is in their development. While pubic hair development goes in a certain order, pubic hair can develop sooner in one guy and later in another guy. If you look at the table in the bone age link, notice that the genital and pubic hair results are slightly different at different bone ages. This is because one sequence can race ahead of another sequence in different boys.

Response:

Got it. Thanks! I seem to understand now.