Tanner stages

Assigning the level of current pubertal development to a male or female based on the observable characteristics of physical and sexual development. Pictures or line drawings are used for the individual and/or parent to denote which of five stages of physical maturity (pre-pubertal with no secondary sexual characteristics through to fully post-pubertal with a completed set of these features) the individual is currently at. 

See Axillary hair, Motor Performance Study (Michigan State University), Turner’s syndrome