Secondary Sex Characteristics

Secondary sex characteristics refer to the physical features and traits that develop during puberty in humans. These characteristics are generally distinct from primary sexual characteristics, which involve the reproductive organs and processes.


During puberty, the body undergoes significant changes in response to hormonal signals. These changes are responsible for the development of secondary sex characteristics, which typically differentiate males from females and contribute to sexual dimorphism.

In Males:

  • Facial Hair: Males often develop facial hair, including beard and mustache, as a secondary sex characteristic.
  • Deepening Voice: The vocal cords lengthen and thicken, leading to a deeper voice in males.
  • Broadening of Shoulders: Testosterone promotes the growth of muscle mass, particularly in the upper body, resulting in broader shoulders.
  • Increased Muscle Mass: Males generally experience an increase in muscle size and strength during puberty.
  • Adam’s Apple: The thyroid cartilage, also known as the Adam’s apple, becomes larger and more prominent.

In Females:

  • Development of Breasts: Estrogen stimulates the development of mammary glands, leading to the growth of breasts in females.
  • Widening of Hips: The bones in the pelvis widen to facilitate childbirth and result in a more rounded hip structure in females.
  • Body Hair: Females typically develop finer and less abundant body hair compared to males.
  • Higher Pitched Voice: The larynx (voice box) in females remains smaller, resulting in a higher pitched voice.
  • Changes in Body Fat Distribution: Females tend to accumulate more subcutaneous fat in the breasts, hips, and buttocks.

Differences in secondary sex characteristics play a significant role in sexual attraction and mate selection, as well as in establishing gender identity. These traits are influenced by genetic factors and the interplay of sex hormones, primarily testosterone and estrogen.