The Tanner scale (also known as the Tanner stages or sexual maturity rating (SMR)) is a scale of physical development as

pre-pubescent Preadolescence is a stage of human development following middle childhood and preceding adolescence.New Oxford American Dictionary. 2nd Edition. 2005. Oxford University Press. It commonly ends with the beginning of puberty. Preadolescence is c ...

children A child () is a human being between the stages of childbirth, birth and puberty, or between the Development of the human body, developmental period of infancy and puberty. The term may also refer to an unborn human being. In English-speaking ...

transition into

adolescence Adolescence () is a transitional stage of human Developmental biology, physical and psychological Human development (biology), development that generally occurs during the period from puberty to adulthood (typically corresponding to the age o ...

, and then

adulthood An adult is an animal that has reached full growth. The biological definition of the word means an animal reaching sexual maturity and thus capable of reproduction. In the human context, the term ''adult'' has meanings associated with social an ...

. The scale defines physical measurements of development based on external

primary Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Work ...

and

secondary sex characteristic A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during pubert ...

s, such as the size of the

breast The breasts are two prominences located on the upper ventral region of the torso among humans and other primates. Both sexes develop breasts from the same embryology, embryological tissues. The relative size and development of the breasts is ...

s, length of the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

, volume of the

testes A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of androgens, primarily testosterone. The ...

, and growth of

pubic hair Pubic hair (or pubes , ) is terminal hair, terminal body hair that is found in the sex organ, genital area and pubic region of adolescent and adult humans. The hair is located on and around the sex organs, and sometimes at the top of the inside ...

. This scale was first quantified in 1969 by James Tanner, a British pediatrician, after a two-decade-long study following the physical changes in girls undergoing

puberty Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a female, the testicles i ...

. Due to natural variation, individuals pass through the Tanner stages at different rates, depending in particular on the timing of

. Among researchers who study puberty, the Tanner scale is commonly considered the "gold standard" for assessing pubertal status when it is conducted by a trained medical examiner. In HIV treatment, the Tanner scale is used to determine which regimen to follow for pediatric or adolescent patients on

antiretroviral therapy The management of HIV/AIDS normally includes the use of multiple antiretroviral drugs as a strategy to control HIV infection. There are several classes of antiretroviral agents that act on different stages of the HIV life-cycle. The use of mul ...

(adult, adolescent, or pediatric guidelines). The Tanner scale has also been used in forensics to determine aging, but its usage has decreased due to lack of reliability.

Stages

Adapted from ''Adolescent Health Care: A Practical Guide'' by Lawrence Neinstein.

Genitals (male)

; Tanner I : testicular volume less than 1.5 ml; small

( prepubertal) ; Tanner II : testicular volume between 1.6 and 6 ml; skin on scrotum thins, reddens and enlarges; penis length unchanged ; Tanner III : testicular volume between 6 and 12 ml; scrotum enlarges further; penis begins to lengthen ; Tanner IV : testicular volume between 12 and 20 ml; scrotum enlarges further and darkens; penis further increases in length and starts to increase in breadth ; Tanner V : testicular volume greater than or equal to 20 ml; adult scrotum and penis

Breasts (female)

; Tanner I : no glandular tissue:

areola The human areola (''areola mammae'', or ) is the pigmented area on the breast around the nipple. More generally, an areola is a small circular area on the Human body, body with a different histology from the surrounding Tissue (biology), tissue ...

follows the skin contours of the chest ( prepubertal) ; Tanner II : breast bud forms, with small area of surrounding glandular tissue; areola begins to widen ; Tanner III : breast begins to become more elevated, and extends beyond the borders of the areola, which continues to widen but remains in contour with surrounding breast ; Tanner IV : increased breast sizing and elevation; areola and papilla form a secondary mound projecting from the contour of the surrounding breast ; Tanner V : breast reaches final adult size; areola returns to contour of the surrounding breast, with a projecting central papilla

Pubic hair (both male and female)

; Tanner I : no pubic hair at all ( prepubertal) ; Tanner II : small amount of long, downy hair with slight pigmentation at the base of the

and

scrotum In most terrestrial mammals, the scrotum (: scrotums or scrota; possibly from Latin ''scortum'', meaning "hide" or "skin") or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin ...

(males) or on the

labia majora In primates, and specifically in humans, the labia majora (: labium majus), also known as the outer lips or outer labia, are two prominent Anatomical terms of location, longitudinal skin folds that extend downward and backward from the mons pubis ...

(females) ; Tanner III : hair becomes more coarse and curly, and begins to extend laterally ; Tanner IV : adult-like hair quality, extending across pubis but sparing medial thighs ; Tanner V : hair extends to medial surface of the thighs

Height

During Tanner V, females stop growing and reach their adult height. Usually, this happens in their mid teens at 14 or 15 years for females. Males also stop growing and reach their adult height during Tanner V; usually this happens in their late teens at 16 to 17 years, but can be a lot later, even into the early 20s.

Historical data

In 1970, boys reached the last Tanner stage, the postpubertal stage, on average at the age of 14.9 years and girls around the age of 14 depending on social class and the particular study. In the nearly fifty years since those studies, the ages at which children are beginning puberty has only declined: () "The age of puberty, especially female puberty, has been decreasing in western cultures for decades now ..for example, at the turn of the 20th century, the average age for an American girl to get her period was 16 or 17. Today, that number has decreased to 12 or 13 years."

Criticism

The scale has been criticized by the

pornography Pornography (colloquially called porn or porno) is Sexual suggestiveness, sexually suggestive material, such as a picture, video, text, or audio, intended for sexual arousal. Made for consumption by adults, pornographic depictions have evolv ...

industry for its potential to lead to false

child pornography Child pornography (also abbreviated as CP, also called child porn or kiddie porn, and child sexual abuse material, known by the acronym CSAM (underscoring that children can not be deemed willing participants under law)), is Eroticism, erotic ma ...

convictions, such as in the case of pornographic actress Lupe Fuentes where in 2009 United States federal authorities used it to assert that she was not an adult despite her age. Fuentes personally appeared at the trial and provided documentation that showed that the DVDs in question were legally produced. Tanner, the author of the classification system, has argued that age classification using the stages of the scale misrepresents the intended use. Tanner stages do not match with chronological age, but rather maturity stages and thus are not diagnostic for age estimation.

References

External links

The Male Tanner stages

* * {{Authority control Medical scales Endocrinology Paraphilias Pediatrics Sexology Sexuality and age Puberty 1969 introductions