Table 5.

Mean Age of Transition to Sexual Maturity Stages 2 and 3 and Menarche

Mean (yr)*SDSE
BreastTanner Stage 2
 White9.961.820.032
 Afr.-Am.8.871.930.093
BreastTanner Stage 3
 White11.301.420.032
 Afr.-Am.10.191.420.084
Pubic HairTanner Stage 2
 White10.511.670.032
 Afr.-Am.8.782.000.094
Pubic HairTanner Stage 3
 White11.531.210.029
 Afr.-Am.10.351.630.093
Any developmentTanner Stage 2
 White9.711.870.031
 Afr.-Am.8.112.020.091
Any developmentTanner Stage 3
 White11.141.420.030
 Afr.-Am.9.851.590.088
Menarche
 White12.881.200.061
 Afr.-Am.12.161.210.118
  • Abbreviations: SD, standard deviation; SE, standard error.

  • * P < 0.001 for the comparisons between African-American and white girls for each stage of development of breast, pubic hair, and menses.

  • Denotes the appearance of either breast or pubic hair or both.