• Prepubertal, small penis and testes
• No pubic hair growth

Sexual Development Stage 2:
Age: 9 - 13 years

• Testes grow
• Scrotal skin becomes redder and coarser
• Sparse, fine hair develops at the base of the penis

Sexual Development Stage 3:
Age: 12 - 14 years

• Penis lengthens, with small increase in diameter
• Scrotum and testes continue to grow
• Pubic hair increases in amount and becomes darker, coarser, and curly

Sexual Development Stage 4:
Age: 12 - 15 years

• Penis and testes continue to grow
• Pubic hair increases in amount and becomes darker, coarser, and curly

Sexual Development Stage 5:
Age: 14 - 18 years

• Penis is at its full adult size
• Pubic hair is at its adult color, texture, and distribution