Although fine vellus hair is present in the area in childhood, pubic hair is considered to be the heavier, longer and coarser hair that develops during puberty as an effect of rising levels of androgens in males and estrogens in females. Pubic hair differs from other hair on the body and is a secondary sex characteristic. Many cultures regard pubic hair as erotic, and in most cultures pubic hair is associated with the genitals, which both men and women are expected to keep covered at all times. In some cultures, it is the norm for pubic hair to be removed, especially of females; the practice is regarded as part of personal hygiene. In other cultures, the exposure of pubic hair (for example, when wearing a swimsuit) may be regarded as unaesthetic or embarrassing and is therefore trimmed or otherwise styled to avoid it being visible. Pubic hair fetishism, or pubephilia, is where a person becomes sexually aroused by the sight or feel of human pubic hair.