When the breasts start to grow, this is normally the first sign of puberty that can be seen on the outside of a girl's body. This usually happens when girls are about the age of years. A lump that is a bit hard appears in each breast under the areola, which is the dark ring around the nipple. The lump in one breast may grow before the other one.  This is called breast budding.  Within six to 12 months, both breasts will have started growing. The swelling can be felt and seen outside the edges of the areolae. About one and a half to two years after the breasts first start growing, they are close to the shape and size of an adult woman's breasts. The nipple and areola may be on a smaller mound on each breast. This small mound usually goes away when each breast is fully grown.  Whether the breasts are small or large depends on how much fat there is in the body.  
In boys, testicular enlargement is the first physical manifestation of puberty (and is termed gonadarche ).  Testes in prepubertal boys change little in size from about 1 year of age to the onset of puberty, averaging about 2–3 cm in length and about –2 cm in width. The size of the testicles is among the parameters of the Tanner scale for male genitals , from stage I which represents a volume of less than ml, to stage V which represents a testicular volume of greater than 20 ml. Testicular size reaches maximal adult size about 6 years after the onset of puberty. After the boy's testicles have enlarged and developed for about one year, the length and then the breadth of the shaft of the penis will increase and the glans penis and corpora cavernosa will also start to enlarge to adult proportions.  While 18–20 cm 3 is an average adult size, there is wide variation in testicular size in the normal population. 
Verbal memory scores are frequently used as one measure of higher level cognition . These scores vary in direct proportion to estrogen levels throughout the menstrual cycle, pregnancy, and menopause. Furthermore, estrogens when administered shortly after natural or surgical menopause prevents decreases in verbal memory. In contrast, estrogens have little effect on verbal memory if first administered years after menopause.  Estrogens also have positive influences on other measures of cognitive function.  However the effect of estrogens on cognition is not uniformly favorable and is dependent on the timing of the dose and the type of cognitive skill being measured.