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Definition

Puberty is the period of human development during which physical growth and sexual maturation occurs.

Description

Beginning as early as age eight in girls—and two years later, on average, in boys—the hypothalamus (part of the brain) signals hormonal change that stimulates the pituitary. In turn, the pituitary releases its own hormones called gonadotrophins that stimulate the gonads and adrenals. From these glands come a flood of sex hormones—androgens and testosterone in the male, estrogens and progestins in the female—that regulate the growth and function of the sex organs. It is interesting to note that the gonadotrophins are the same for males and females, but the sex hormones they induce are different.

In the United States, the first sign of puberty occurs on average at age 11 in girls, with menstruation and fertility following about two years later. Boys lag behind by about two years. Puberty may not begin until age 16 in boys and continue in a desultory fashion on past age 20. In contrast to puberty, adolescence is more of a social/cultural term referring to the interval between childhood and adulthood.

— J. Ricker Polsdorfer, MD



 
 
Dictionary: pu·ber·ty  (pyū'bər-tē) pronunciation
n.

The stage of adolescence in which an individual becomes physiologically capable of sexual reproduction.

[Middle English puberte, from Old French, from Latin pūbertās, from pūbēs, pūber-, adult.]

pubertal pu'ber·tal or pu'ber·al (-bər-əl) adj.
 

Puberty marks the point in human development where both males and females gain the capability to procreate. Puberty occurs during adolescence, which begins as early as age 10 and is usually completed by age 17. For girls, a rising level of oestrogen (female hormone) sets the process in motion. Pelvis and breast development are followed by a spurt in height and then the growth of underarm and pubic hair. Finally, menarche, the beginning of the first menstrual cycle, occurs. Ovulation does not automatically coincide with menarche. It may take as many as forty cycles for ovulation to become a regular part of the menstrual cycle. Though they are uniform in order, the age of onset, pace, and duration of these changes vary widely from one individual to another. Since the beginning of the twentieth century, the average age of first menstruation has declined. In the US, it decreased from about 14 years old in 1900 to 12 years old in 1975. Scientists attribute this change to better living standards, particularly in regard to diet. In males a sharp increase in androgen (male hormone) and growth hormone spawns skeletal development, followed by the lowering of the voice, the growth of facial hair, increase in sex organ size, height, spermatogenesis, and muscle development. The outward physical signs of puberty tend to occur earlier in girls than in boys, particularly the growth spurt.

While the physiological terrain of puberty is clearly mapped, psychological and cultural changes meander in a much less orderly direction. Adolescence, by definition, begins in childhood and ends with young adulthood. To negotiate successfully this stage of human development, girls and boys must develop conceptual powers, independence, a sense a their own identity, and a way to make moral or ethical decisions. All the while, they are grappling with their emerging sexuality, marked by heightened sexual development and sexual interest.

The ‘normal’ routes through puberty vary according to cultural standards, socio-economic class, gender roles, and family structure. Some cultures and religions have clearly established rituals to mark puberty. The Jewish bar mitzvah, for example, celebrates a boy's entry into adolescence, and most of tribal Africa holds puberty rituals which may include dance, music, or seclusion.

According to John and Virginia Demos, adolescence is a rather modern invention which ‘did not exist before the last two decades of the nineteenth century.’ Its invention resulted from an increased focus on children among the middle classes, who no longer needed their children's labour for family survival and so re-defined childhood and puberty in more psychological and social terms. In addition, the nineteenth-century research of social scientists such as G. Stanley Hall and Sigmund Freud emphasized distinct categorizations for each stage of human development. The influential Hall defined adolescence as stressful, violent, and crisis-ridden.

— Margaret A. Lowe

Bibliography

  • John and Virginia Demos (1973). Adolescence in historical perspective. In The American Family in Social-Historical Perspective. St Martin's Press, New York

See also development and growth: school age and adolescence; sex hormones.

 

The period between the first appearance of pubic hair and (in females) the first menstrual flow, or (in males) the first development of active sperm. The age of puberty varies: in females it is usually between 9 and 15 years, and in males between 11 and 14 years. During puberty, young people undergo quite dramatic physical and psychological changes. Regular, well-structured exercise and sport can help them to cope with these changes by providing emotional and physical release. Involvement in sport can also encourage personal responsibility for health and an interest in sound nutrition. In addition to its cardiovascular benefits, regular aerobic exercise may also help to ease menstrual pain in girls. Despite all these advantages, some types of exercise are dangerous during puberty because bones are still growing and the cartilaginous growth zones (epiphyseal discs) are easily damaged. Consequently, hard anaerobic exercise and training with heavy weights should not take place until two years after the final growth spurt, which may be any time between 10 and 18 years. Excessive aerobic activity, such as long-distance running, can also place intolerable stresses on joints and soft tissues causing permanent damage.

 
Thesaurus: puberty

noun

    The time of life between childhood and maturity: adolescence, greenness, juvenescence, juvenility, salad days, spring, youth, youthfulness. See youth/age/maturity.

 
Antonyms: puberty

n

Definition: young adulthood
Antonyms: adulthood


 
(pyōō′burtē)
n

The age at which the reproductive system becomes functional, with concurrent development of secondary sex characteristics. Marked by increased estrogenic activity in the female and rise of androgenic activity in the male.

 

Definition

Puberty is the period of human development during which physical growth and sexual maturity occurs.

Description

The word puberty is derived from the Latin pubertas, which means adulthood. Puberty is initiated by hormonal changes triggered by a part of the brain called the hypothalamus, which stimulates the pituitary gland, which in turn activates other glands as well. These changes begin about a year before any of their results are visible. Both the male reproductive hormone testosterone and female hormone estrogen are present in children of both sexes. However, their balance changes at puberty, with girls producing relatively more estrogen and boys producing more testosterone.

Beginning as early as age eight in girls—and two years later, on average, in boys—the hypothalamus signals hormonal change that stimulates the pituitary. In turn, the pituitary releases its own hormones called gonadotrophins that stimulate the gonads and adrenals. From these glands come a flood of sex hormones—androgen and testosterone in the male, estrogen and progestin in the female—that regulate the growth and function of the sex organs. It is interesting to note that the gonadotrophins are the same for males and females, but the sex hormones they induce are different.

The experience of puberty is new and unusual for both boys and girls. It is not something that happens overnight, but rather it is a process that occurs in stages and at different ages for different people. It is perfectly normal, for example, for one person to have already started developing while one's best friend of the same age has not. The age at which puberty begins can vary widely between individuals. Timing of onset is affected by genetic factors, body mass, nutritional state, and general health.

School Age

The average age for first signs of breast development in girls is about 10.5 years, with menstruation and fertility following about two years later. Average age for first signs of testicle enlargement in boys is 11.5 years. Puberty may not begin until age 16 in boys and continue in a random fashion beyond age 20. In contrast to puberty, adolescence is more a social/cultural term that refers to the interval between childhood and adulthood. The duration of puberty, from time of onset to completion, varies less between children than does the age of onset. Duration of puberty in girls from onset of breast development to cessation of growth is roughly five years. Duration of puberty in boys from first testicle enlargement to cessation of growth is about six years.

Puberty has been divided into five Sexual Maturity Rating (SMR) stages by two doctors, W. Marshall and J. M. Tanner. These ratings are often referred to as Tanner Stages one through five. Staging is based on pubic hair growth, on genital development, and female breast development. Staging helps determine whether development is normal for a given age. Both sexes also grow armpit hair and develop pimples. Males develop muscle mass, a deeper voice, and facial hair. Females redistribute body fat. Along with the maturing of the sex organs, there is a pronounced growth spurt averaging three to four inches (8–10 centimeters) and culminating in full adult stature. Puberty can be early or delayed.

Puberty Stages in Girls

  • Stage One (approximately between the ages of eight and eleven): The ovaries enlarge and hormone production starts, but external development is not yet visible.
  • Stage Two (approximately between the ages of eight and fourteen): The first external sign of puberty is usually breast development. At first breast buds develop. The nipples will be tender and elevated. The area around the nipple (the aureole) will increase in size. The first stage of pubic hair may also be present at this time. It may be coarse and curly or fine and straight. Height and weight increase at this time. The body gets rounder and curvier.
  • Stage Three (approximately between the ages of nine and 15): Breast growth continues and pubic hair gets coarser and darker. During this stage, whitish discharge from the vagina may be present. For some girls, this is the time that the first menstrual period begins.
  • Stage Four (approximately from ages 10 to 16): Some girls notice that their aureoles get even darker and separate into a little mound rising above the rest of the breast. Pubic hair may begin to have a more adult triangular pattern of growth. If it did not happen in Stage Three, menarche (first menstruation) should start now. Ovulation may start now, too. But it will not necessarily occur on a regular basis. (It is possible to have regular periods even if ovulation does not occur every month.)
  • Stage Five (approximately between ages 12 and 19): This is the final stage of development. Full height is reached, and young women are ovulating regularly. Pubic hair is filled in, and the breasts are developed fully for the body.

Puberty Stages in Boys

  • Stage One (approximately between ages nine and 12): No visible signs of development occur, but, internally, male hormones become a lot more active. Sometimes a growth spurt begins at this time.
  • Stage Two (approximately between ages nine to 15): Height increases and the shape of the body changes. Muscle tissue and fat develop at this time. The aureole, the dark skin around the nipple, darkens and increases in size. The testicles and scrotum grow, but the penis probably does not. A little bit of pubic hair begins to grow at the base of the penis.
  • Stage Three (approximately between ages 11 and 16): The penis starts to grow during this stage. It tends to grow in length rather than width. Pubic hair is getting darker and coarser and spreading to where the legs meet the torso. Also, boys continue to grow in height, and even their faces begin to appear more mature. The shoulders broaden, making the hips look smaller. Muscle tissue increases and the voice starts to change and deepen. Finally, facial hair begins to develop on the upper lip.
  • Stage Four (approximately 11 to 17): At this time, the penis starts to grow in width, too. The testicles and scrotum also continue to grow. Hair may begin to grow on the anus. The texture of the penis becomes more adult-looking. Underarm and facial hair increases as well. Skin gets oilier, and the voice continues to deepen.
  • Stage Five (approximately 14 to 18): Boys reach their full adult height. Pubic hair and the genitals look like an adult man's do. At this point, too, shaving is a necessity. Some young men continue to grow past this point, even into their twenties.

Common Problems

When puberty occurs outside the age limits considered normal parents may be prompted to search for the cause. As health and nutrition have improved over the past few generations, there has been a gradual decrease in the average age for the onset of puberty. These causes of early or late puberty may include the following:

  • Excess hormone stimulation is the cause for early puberty. It can come from the brain in the form of gonadotrophins or from the gonads and adrenals. Functioning tumors may cause overproduction of sex hormones. Brain overproduction of factors promoting sex hormone production can also be the result of brain infections or injury.
  • Likewise, delayed puberty is due to insufficient hormone. If the pituitary output is inadequate, so will be the output from the gonads and adrenals. By contrast, a normal pituitary overproduces if it senses there are not enough hormones in the circulation.
  • There are several congenital disorders called polyglandular deficiency syndromes that include failure of hormone output. Children with these syndromes do not experience normal puberty, but it may be induced by giving them hormones at the proper time.
  • Finally, there are in females abnormalities in hormone production that produce male characteristics, so called virilizing syndromes. Should one of these appear during adolescence, it will disturb the normal progress of puberty. Notice that virilizing requires abnormal hormones in the female, while feminizing results from absent hormones in the male. Each embryo starts out life as female. Male hormones transform it if they are present.

Delayed or early puberty requires measurement of the several hormones involved to determine which are lacking or which are in excess. There are blood tests for each one. If a tumor is suspected, imaging of the suspect organ needs to be done with x rays, computed tomography scans (CT scans), or magnetic resonance imaging (MRI).

Puberty is a period of great stress, both physically and emotionally. The psychological changes and challenges of puberty are made infinitely greater if its timing is off.

In early puberty, the offending gland or tumor may require surgical attention, although there are several drugs as of 2004 that counteract hormone effects. If delayed, puberty can be stimulated with the correct hormones. Treatment should not be delayed because necessary bone growth is also affected.

Early puberty often begins before age eight in girls, triggering the development of breasts and hair under the arms and in the genital region. The onset of ovulation and menstruation also may occur. In boys, the condition triggers the development of a large penis and testicles, with spontaneous erections and the production of sperm. Hair grows on the face, under arms, and in the pubic area, and acne may become a problem.

Several studies indicate an increase in incidences of early puberty and other forms of early sexual development in the United States. Sexual development in children seven years of age and younger should be evaluated by a physician. In some cases, early sexual development can be caused by a tumor or other pathological conditions. Properly administered hormones can restore the normal growth pattern.

Parental Concerns

Most experts suggest that parents begin short and casual discussions about the body changes that occur in puberty with their children by the age of seven or eight. Offering the child reading materials about puberty can impart information to the young person without the awkwardness that may characterize the parent-child conversations. Parents can then offer their children opportunities to ask questions or to discuss any aspects of puberty and sexuality that may arise from their reading.

It is also a good idea for parents to talk to their children about proper hygiene at the onset and during puberty. While good hygiene is important for everyone at any age, it can require greater care at the onset of puberty. Hormones produced by the maturing body bring about physical changes that require greater attention when it comes to hygiene. For a young girl or boy, this means taking more time to clean the body, especially the sexual organs, to treat acne, use mouthwash for bad breath, and deodorant for stronger body odor.

When a boy or girl begins to go through puberty, the body produces more perspiration because sweat glands, some of which are located near the underarms, become more active. More perspiration means a different type of body odor, one that is stronger and similar to an adult's. Daily bathing and showering are enough to control body odor, along with deodorants and antiperspirants.

Boys should be instructed to wash their genitals every day. This includes washing the penis, the scrotum that holds the testicles, the anus, and pubic hair with water and mild soap. Uncircumcised boys need to be instructed that the foreskin should be pulled down daily to expose the tip of the penis, which should then be washed with mild soap and water.

In girls, it is perfectly natural to have a slight sweet smell from the vagina that is inoffensive. A strong, foul odor indicates a possible infection. With treatment, the infection goes away and so does the strong odor. Vaginal discharge is a necessary part of the body's regular functioning. Normal discharge, usually clear to white, is part of the body's self-cleaning process. As discharge leaves the body, it takes bacteria with it, which helps prevent vaginal infections. Parents should stress that girls clean the vaginal area with a mild soap and water

Puberty
  BoysGirls
SOURCE: Child Development Institute. http://www.childdevelopmentinfo.com. 2005.
Stage one Prepubertal: no sexual development Prepubertal: no sexual development
Stage two Testes enlarge Breast budding
  Body odor First pubic hair
    Body odor
    Height spurt
Stage three Penis enlarges Breasts enlarge
  Pubic hair starts growing Pubic hair darkens, becomes curlier
  Ejaculation (wet dreams)  
    Vaginal discharge
Stage four Continued enlargement of testes and penis Onset of menstruation
    Nipple is distinct from areola
  Penis and scrotal sac deepen in color  
  Pubic hair curlier and coarser  
  Height spurt  
  Male breast development  
Stage five Fully mature male Fully mature female
  Pubic hair extends to inner thighs Pubic hair extends to inner thighs
  Increases in height slow, then stop Increases in height slow, then stop

on a regular basis to help control bacteria growth and limit infections.

When to Call the Doctor

Parents should consult a pediatrician or physician when their child shows signs of either early or delayed puberty.

Resources

Books

Bailey, Jacqui, and Jan McCafferty. Sex, Puberty, and All that Stuff. Hauppauge, NY: Barrons Educational Series, 2004.

Madaras, Lynda, et al.What's Happening to My Body? Book for Boys. New York: Newmarket Press, 2000.

——. What's Happening to My Body? Book for Girls. New York: Newmarket Press, 2000.

McCave, Marta. Puberty's Wild Ride. Philadelphia: Family Planning Council, 2004.

Periodicals

Brunk, Doug, "Navigating Tx [Treatment] of Boys on the Brink of Puberty." Pediatric News (October 2001): 31.

Herman-Giddens, Marcia E., et al. "Navigating the Recent Articles on Girls' Puberty in Pediatrics: What Do We Know and Where Do We Go from Here?" Pediatrics (April 2004): 911–17.

"New Study Identifies Gene Signaling Puberty." Genomics & Genetics Weekly (November 14, 2003): 33.

Ramsayer, K. "Pesticide May Hinder Development in Boys." Science News (December 13, 2003): 372–73.

Wang, Youfa. "Is Obesity Associated with Early Sexual Maturation? A Comparison of the Association in American Boys Versus Girls." Pediatrics (November 2002): 903–10.

Wellbery, Caroline. "Cut-Off Age for Precocious Puberty Is Too Young." American Family Physician (May 1, 2003): 2001.

Organizations

American Academy of Pediatrics. 141 Northwest Point Blvd., Elk Grove Village, IL 60007. Web site: www.aao.org.

Precocious Puberty Support Network. c/o MAGIC Foundation, 6645 W. North Ave., Oak Park, IL 60302. Web site: www.magicfoundation.org.

Web Sites

"Female Puberty." Available online at www.teenpuberty.com/index.php?section=female (accessed October 29, 2004).

"Male Puberty." Available online at www.teenpuberty.com/index.php?section=male (accessed October 29, 2004).

"Puberty and Adolescence." National Institutes of Health. Available online at www.nlm.nih.gov/medlineplus/ency/article/001950.htm (accessed October 29, 2004).

[Article by: J. Ricker Polsdorfer, MD Ken R. Wells]



 

In human physiology, the period of first becoming capable of reproducing sexually. Occurring at about age 12 in girls and age 14 in boys, puberty is characterized by the maturing of the genital organs, development of secondary sex characteristics, and, in girls, onset of menstruation. Both sexes experience a swift increase in body size and changes in body shape and composition. Puberty marks the beginning of adolescence.

For more information on puberty, visit Britannica.com.

 

pubescence

A period in the life course between the appearance of pubic hair and, in females, the first menarche, or, in males, the first development of sperm. Puberty varies, but in females it usually occurs between 9 and 15 years, while in males it usually occurs between 11 and 14 years.

 
(pyū'bərtē) , period during which the onset of sexual maturity occurs. It usually takes place between the ages of 10 and 15 in both sexes but sometimes occurs as early as 7 or 8 years of age in females. The pituitary gland secretes hormones that stimulate enlargement and development of the sex organs, which thus become capable of reproduction. The appearance of secondary sex characteristics also occurs during puberty. In females the reproductive cycle of ovulation and menstruation begins, pubic hair appears, and development of the breasts and other body contours takes place. Physical changes in males include production and discharge of semen, appearance of facial and body hair, and deepening of the voice. Skin difficulties, such as acne, may affect both sexes. Puberty, a transition period coinciding with adolescence, involves both physiological and psychological adjustments. It is often marked by emotional stress arising as the adolescent relinquishes childhood behavior patterns and adopts those of an adult.


 
Psychoanalysis: Puberty

Puberty was originally defined anatomically and physiologically as the appearance of secondary signs of sexual maturation that mark the beginning of the adolescent process which will put an end to the period of childhood that had been prolonged by the period of latency. The concepts of puberty and adolescence have been increasingly considered as belonging to the field of psychoanalysis only progressively.

Of course the chapter on the "Transformations of Puberty" in Three Essays on the Theory of Sexuality (1905d) is the essential text by Freud on this subject, but to ascertain the reason for the key place this stage assumes in metapsychological development, it is necessary to go back to the early hypotheses on trauma. The seduction theory formulated in the Studies on Hysteria (1895d) assumed in effect two distinct scenes separated by puberty. It is this breakthrough from the presexual (albeit already oriented by the phallus to the genital) which gives both chronological and logical meaning to the twin ideas of latency and deferred action.

For Freud therefore, above and beyond the impact it has on the body and the psychological implications of this, puberty is something that operates: initially as a real trauma, then later as a logical operand in the seduction-fantasy, where it served to delineate boundaries. That being said, the 1905 essay on puberty and all the preceding work was to be enriched by later discoveries, such as the 1914 theory of narcissism and, in 1924, the second topology and the death drive hypothesis.

What is at stake in puberty is clear from the outset: "With the arrival of puberty, changes set in which are destined to give infantile sexual life its final, normal shape. The sexual instinct has hitherto been predominantly auto-erotic; it now finds a sexual object" (1905d, p. 206). Freud then raises five questions, all of which are still being asked, on the nature of puberty: First of all, how is the erotic destiny of each person, perversion aside, determined by the way in which the pregential drives are simultaneously placed in submission to and in the service of genitality, which is the sign of normality? Secondly, what is the role, necessary but not sufficient, of the "chemical" factor in causing sexual tension and pleasure, given that even neurosis "greatly resembles" a state of intoxication and want? Thirdly, according to the theory of narcissism how will ego libido and object libido be fused in this moment of anticipated tension and complementarity between the currents of love and sex? Fourthly, how is, in a final renunciation of bisexuality, the man's "more logical" development going to then be differentiated from the "involution" of the young woman who willingly rejoins her initial, oral sexual orientations at the same time as she accedes to genitality? Fifth and finally, in what way is the new sexual object, a semblance of the Other sex, at once both new and rediscovered on the basis of the primal objects, the ancestors of the Other sex? In his conclusion devoted to the risks associated with homosexual inversion occasioned by both familial and social milieus, Freud alerts us to the fact that this accession to a sexual relationship which assumes responsibility for the difference between the sexes, does not occur automatically.

For a long time after Freud puberty remained a secondary preoccupation for psychoanalysts. Instead, under the influence of child analysts and fueled in particular by the debates between Anna Freud and Melanie Klein, interest tended to focus on the relationship between earliest infancy and the oedipal period, with adolescence being considered as little more than the outcome of precocious determinants. On the other hand in the field of psychopathology, the side of adolescence, dissociated from puberty, concerned with the trials of socialization and its psycho-pathological failures, became the privileged focus of study in the texts on this period (Siegfried Bernfeld, August Aichhorn).

Only recently, and especially in Great Britain and France, has interest been renewed in puberty as distinct from the ensemble of adolescent processes, and designated as such as being their origin. Donald Winnicott was the first to recall that it is sexual maturation, not only social exigencies, which reactivate oedipal difficulties, giving rise to murderous and incestuous feelings which were all too easily repressed in childhood when they were unrealizable, and calling for a second oedipal working-through, subject to new ups and downs. Moses Laufer has elaborated on this approach by explicating the more-or-less pathological crises of adolescence using the concept of breakdown, reworked from Winnicott, but which is for Laufer a developmental fracture in the integration of the body image which, following puberty, needs to then incorporate the genital organs and allow for a new compromise between masturbatory fantasy and the demands of the superego. With this Philippe Gutton was able to produce the concept of the "pubertal, which is to the psyche what puberty is to the body." Although he left room for debate, Gutton distinguished distinctly and chronologically between the category of feelings that refashion the aim of the drive from the phallic to the genital and are oriented towards a new, complementary, part object—and the adolescens process, which is a reconstruction of referents and ideals that this genital identity imposes.

On the Lacanian side, which has proved more reticent with respect to the psychogenetic approach, the texts are few and far between: For Françoise Dolto, puberty is a third "moment of synthesis" (after the mirror stage and the Oedipus complex), in the construction of an unconscious body image. Jean-Jacques Rassial views puberty in its somatic, but also psychic aspects, as the Real blow that necessitates an Imaginary reconstruction and a new Symbolic foundation, insofar as this is an adolescent function.

The production of the concept of puberty points toward a certain number of theoretical modifications: First off (and this is borne out by clinical experience), the topological status of puberty, be it individual or social, and which affects not only the ego but also the id and the superego, affirms the autonomy of the psychical from the somatic and the social, because psychic puberty does not always occur at the same time as these two other puberties. Secondly, from a dynamic point of view, Freudian precepts hold that the conflicts taking place during this time are not only the repetition of earlier conflicts, and therefore all psychogenesis, and particularly the pre-pubertal function of the latency period, needs to be rethought. Thirdly, the economic function of the phallus, between drive and representation, is put into question by its separation during this period from the genital that cannot, after all, be reduced to just its imaginary employment.

As is already apparent in Freud's texts, the transformations of puberty are not a simple issue of psychogenetics, but raise the question of the function of sexuality as a whole. In other words, behind the story that goes from infantile sexuality to so-called adult normality there lies another, about the infantilism of a sexuality that destines the sexual relationship to its failures, which diverge according to the sexual genital in question.

Bibliography

Freud, Sigmund. (1905d). Three essays on the theory of sexuality. SE, 7: 123-243.

Gutton, Philippe. (1991). Le pubertaire. Paris: Presses Universitaires de France.

Laufer, Moses, and Laufer, Egle. (1984). Adolescence and developmental breakdown: a psychoanalytic view. New Haven, CT: Yale University.

Perret-Catipovic, Maja, and Ladame, François (Eds.). (1997). Adolescence and psychoanalysis: The story and the history (Philip Slotkin, Trans.). London: Karnac.

Rassial, Jean-Jacques. (1990). L'Adolescent et le psychanalyse. Paris: Payot.

Further Reading

Bloch, H. Spencer. (1995). Adolescent development, psycho-pathology, and treatment. Madison, CT: International University Press.

Laufer, Moses. (1996). The psychoanalyst of the adolescent. Psychoanalytic Study of the Child, 51, 512-521.

—JEAN-JACQUES RASSIAL

 

Pertaining to or emanating from puberty.

  • p. period — the period approaching puberty when gonadal function, accessory sex gland function and behavior develop to the point where reproduction is possible.
 
Wikipedia: puberty

Puberty refers to the process of physical changes by which a child's body becomes an adult body capable of reproduction. Puberty is initiated by hormone signals from the brain to the gonads (the ovaries and testes). In response, the gonads produce a variety of hormones that stimulate the growth, function, or transformation of brain, bones, muscle, skin, breasts, and reproductive organs. Growth accelerates in the first half of puberty and reaches completion by the end. Before puberty, body differences between boys and girls are almost entirely restricted to the genitalia. During puberty major differences of size, shape, composition, and function develop in many body structures and systems. The most obvious of these are referred to as secondary sex characteristics.

In a strict sense, the term puberty (and this article) refers to the bodily changes of sexual maturation rather than the psychosocial and cultural aspects of adolescent development. Adolescence is the period of psychological and social transition between childhood and adulthood. Adolescence largely overlaps the period of puberty but its boundaries are less precisely defined and it refers as much to the psychosocial and cultural characteristics of development during the teen years as to the physical changes of puberty.

Differences between male and female puberty

Two of the most significant differences between puberty in girls and puberty in boys are the age at which it begins, and the major sex steroids involved.

Although there is a wide range of normal ages, on average, girls begin the process of puberty about 1-2 years earlier than boys, and reach completion in a shorter time.[1] Girls attain adult height and reproductive maturity about 4 years after the first physical changes of puberty appear. In contrast, boys accelerate more slowly but continue to grow for about 6 years after the first visible pubertal changes.

The hormone that dominates female development is estradiol, an estrogen. While estradiol promotes growth of breasts and uterus, it is also the principal hormone driving the pubertal growth spurt and epiphyseal maturation and closure.[2] Estradiol levels rise earlier and reach higher levels in women than in men.

In boys, testosterone, an androgen, is the principal sex steroid. While testosterone produces all the male changes characterized as virilization, a substantial product of testosterone metabolism in males is estradiol, though levels rise later and more slowly than in girls. The male growth spurt also begins later, accelerates more slowly, and lasts longer before the epiphyses fuse. Although boys are 2 cm taller than girls before puberty begins, adult men are on average about 13 cm (5.2 inches) taller than women. Most of this sex difference in adult heights is attributable to a later onset of the growth spurt and a slower progression to completion.[3] a direct result of the later rise and lower adult male levels of estradiol.

Physical changes in boys

Testicular size, function, and fertility

In boys, testicular enlargement is the first physical manifestation of puberty (and is termed gonadarche).[4] Testes in prepubertal boys change little in size from about 1 year of age to the onset of puberty, averaging about 2–3 cc in volume and about 1.5-2 cm in length. Testicular size continues to increase throughout puberty, reaching maximal adult size about 6 years later.[5] While 18-20 cc is reportedly an average adult size, there is wide variation in the normal population.[6]

The testes have two primary functions: to produce hormones and to produce sperm. The Leydig cells produce testosterone (as described below), which in turn produces most of the changes of male sexual maturation and maintains libido. However, most of the increasing bulk of testicular tissue is spermatogenic tissue (primarily Sertoli and interstitial cells). The development of sperm production and fertility in males is not as well documented. Sperm can be detected in the morning urine of most boys after the first year of pubertal changes (and occasionally earlier).

Genitalia

A boy's penis grows little from the fourth year of life until puberty. After the penile growth of early infancy the average childhood penile length is about 7 cm. The prepubertal genitalia are described as stage 1. Within months after growth of the testes begins, rising levels of testosterone promote growth of the penis and scrotum. This earliest discernible beginning of pubertal growth of the genitalia is referred to as stage 2.[7] The penis continues to grow until about 18 years of age, reaching an average stretched adult size of about 13 cm.[8]

Although erections and orgasm occur in prepubertal boys, they become much more common during puberty, accompanied by a markedly increased libido. Ejaculation becomes possible early in puberty. Prior to this, boys may experience dry orgasms. Emission of seminal fluid may occur due to masturbation or spontaneously during sleep (commonly termed a wet dream, and more clinically called a nocturnal emission). The ability to ejaculate is a fairly early event in puberty compared to the other characteristics.[9] However, in parallel to the irregularity of the first few periods of a girl, for the first one or two years after a boy's first ejaculation, his seminal fluid may contain few active sperm.

If the foreskin of a boy does not become retractable during childhood, it normally begins to retract during puberty. This occurs as a result of the increased production of testosterone and other hormones in the body.

Pubic hair in boys

Pubic hair often appears on a boy shortly after the genitalia begin to grow. As in girls, the first appearance of pubic hair is termed pubarche and the pubic hairs are usually first visible at the dorsal (abdominal) base of the penis. The first few hairs are described as stage 2. Stage 3 is usually reached within another 6–12 months, when the hairs are too numerous to count. By stage 4, the pubic hairs densely fill the "pubic triangle." Stage 5 refers to spread of pubic hair to the thighs and upward towards the navel as part of the developing abdominal hair.

Body and facial hair

In the months and years following the appearance of pubic hair, other areas of skin which respond to androgens develop heavier hair (androgenic hair) in roughly the following sequence: underarm (axillary) hair, perianal hair, upper lip hair, sideburn (preauricular) hair, periareolar hair, and the rest of the beard area. Arm, leg, chest, abdominal, and back hair become heavier more gradually. There is a large range in amount of body hair among adult men, and significant differences in timing and quantity of hair growth among different ethnic groups.

Voice change

Under the influence of androgens, the voice box, or larynx, grows in both genders. This growth is far more prominent in boys, causing the male voice to drop, sometimes abruptly but rarely "over night", about one octave, because the longer and thicker vocal folds have a lower fundamental frequency. Voices never "break." A typical 12-year old boy's larynx is larger, even before voice change, than an adult woman's. Occasionally, voice change is accompanied by unsteadiness of vocalization in the early stages of untrained voices. Most of the voice change happens during stage 4 of male puberty around the time of peak growth. However, it usually precedes the development of significant facial hair by several months to years.

Height growth

In boys, growth begins to accelerate about 9 months after the first signs of testicular enlargement and the peak year of the growth spurt occurs about 2 years after the onset of puberty, reaching a peak velocity of about 8.5–12 cm or 3.5–5 inches per year. The feet and hands experience their growth spurt first, followed by the limbs, and finally ending in the trunk. Epiphyseal closure and adult height are reached more slowly, at an average age of about 17.5 years. As in girls, this last growth primarily involves the spine rather than the limbs.

Male musculature and body shape

By the end of puberty, adult men have heavier bones and nearly twice as much skeletal muscle. Some of the bone growth (e.g., shoulder width and jaw) is disproportionately greater, resulting in noticeably different male and female skeletal shapes. The average adult male has about 150% of the lean body mass of an average female, and about 50% of the body fat.

This muscle develops mainly during the later stages of puberty, and muscle growth can continue even after a male is biologically adult. The peak of the so-called "strength spurt," the rate of muscle growth, is attained about one year after a male experiences his peak growth rate.

Body odor, skin changes, acne

Rising levels of androgens can change the fatty acid composition of perspiration, resulting in a more "adult" body odor. As in girls, another androgen effect is increased secretion of oil (sebum) from the skin and the resultant variable amounts of acne.

Breast development: pubertal gynecomastia

Estradiol is produced from testosterone in male puberty as well as female, and male breasts often respond to the rising estradiol levels. This is termed gynecomastia. In most boys, the breast development is minimal, similar to what would be termed a "breast bud" in a girl, but in many boys, breast growth is substantial. It usually occurs after puberty is underway, may increase for a year or two, and usually diminishes by the end of puberty. It is increased by extra adipose tissue if the boy is overweight.

Although this is a normal part of male puberty for perhaps half of boys, breast development is usually as unwelcome as upper lip hair in girls, and can be removed surgically if the boy's distress is substantial.

Physical changes in girls

Breast development

The first physical sign of puberty in girls is usually a firm, tender lump under the center of the areola(e) of one or both breasts, occurring on average at about 10.5 years of age.[10] This is referred to as thelarche. By the widely used Tanner staging of puberty, this is stage 2 of breast development (stage 1 is a flat, prepubertal breast). Within six to 12 months, the swelling has clearly begun in both sides, softened, and can be felt and seen extending beyond the edges of the areolae. This is stage 3 of breast development. By another 12 months (stage 4), the breasts are approaching mature size and shape, with areolae and papillae forming a secondary mound. In most young women, this mound disappears into the contour of the mature breast (stage 5), although there is so much variation in sizes and shapes of adult breasts that stages 4 and 5 are not always separately identifiable.[11]

Pubic hair in girls

Pubic hair is often the second unequivocal change of puberty noticed, usually within a few months of thelarche.[12] It is referred to as pubarche and the pubic hairs are usually visible first along the labia. The first few hairs are described as Tanner stage 2.[11] Stage 3 is usually reached within another 6-12 months, when the hairs are too numerous to count and appear on the pubic mound as well. By stage 4, the pubic hairs densely fill the "pubic triangle." Stage 5 refers to spread of pubic hair to the thighs and sometimes as abdominal hair upward towards the navel. In about 15% of girls, the earliest pubic hair appears before breast development begins.[12]

Vagina, uterus, ovaries

The mucosal surface of the vagina also changes in response to increasing levels of estrogen, becoming thicker and a duller pink in color (in contrast to the brighter red of the prepubertal vaginal mucosa).[13] Whitish secretions (physiologic leukorrhea) are a normal effect of estrogen as well.[10] In the next 2 years following thelarche, the uterus and ovaries increase in size, and follicles in the ovaries reach larger sizes.[14] The ovaries usually contain small follicular cysts visible by ultrasound.[15][16]

Menstruation and fertility

The first menstrual bleeding is referred to as menarche, and typically occurs about 2 years after thelarche.[12] The average age of menarche in American girls is about 12.7 years.[12] Menses (menstrual periods) are not always regular and monthly in the first 2 years after menarche.[17] Ovulation is necessary for fertility, but may or may not accompany the earliest menses.[18] According to one study, about 80% of menses are anovulatory in the first year after menarche, and about 50% in the second year, but only 10% of girls were not ovulating after 5 years.[17] However, initiation of ovulation after menarche is not inevitable, and a high proportion of girls with continued irregularity several years from menarche will continue to have prolonged irregularity and anovulation, and are at higher risk for reduced fertility.[19] The word nubility is used commonly in the social sciences to designate achievement of fertility.

Body and facial hair

In the months and years following the appearance of pubic hair, other areas of skin which respond to androgens develop heavier hair (androgenic hair) in roughly the following sequence: underarm (axillary) hair, perianal hair, upper lip hair, sideburn (preauricular) hair, periareolar hair, and hairs along the linea nigra between from the pubic hair to the umbilicus. The amount of hair in those areas is less than the male amount. There is a large range in amount of body hair among adult women, and significant differences in timing and quantity of hair growth among different ethnic groups.

Body shape, fat distribution, and body composition

During this period, also in response to rising levels of estrogen, the lower half of the pelvis widens (providing a larger birth canal).[11] Fat tissue increases to a greater percentage of the body composition than in males, especially in the typical female distribution of breasts, hips, buttocks, thighs, upper arms, and pubis. Progressive differences in fat distribution as well as sex differences in local skeletal growth contribute to the typical female body shape by the end of puberty. At age 10 years, the average girl has 6% more body fat than the average boy, but by the end of puberty the average difference in nearly 50%.[20]

Body odor, skin changes, and acne

Rising levels of androgens can change the fatty acid composition of perspiration, resulting in a more "adult" body odor. This often precedes thelarche and pubarche by 1 or more years. Another androgen effect is increased secretion of oil (sebum) from the skin. This change increases the susceptibility to acne, a characteristic affliction of puberty greatly variable in its severity.[21]

Variations

Typical puberty is described above, but many children vary with respect to timing of onset, tempo, steadiness of continuation, and sequence of events.

Timing of onset

Puberty is a process with a gradual onset beginning with changes of neuronal function in the hypothalamus, resulting in rising hormonal signals between brain and gonads, proceeding to gonadal growth and production of sex steroids, which in turn induce changes in responsive parts of the body. The definition of onset, therefore, depends on the perspective (e.g., hormonal versus physical) and purpose (establishing population normal standards, clinical care of early or late children, or a variety of other social purposes). The most commonly used definition of onset for both social and medical purposes is the appearance of the first physical changes described in this section of this article, but it should be understood that these physical changes are the first outward signs of preceding neural, hormonal, and gonadal function changes that are usually impossible or impractical to detect.

The age at which puberty begins can vary widely between individuals and between populations. Age of puberty is affected by both genetic factors and by environmental factors such as nutritional state or social circumstances. Timing may also be affected by environmental factors (exogenous hormones and environmental substances with hormone-like effects) and there is even evidence that life experiences may play a role as well.

Ethnic/racial differences have been recognized for centuries. For example, the average age of menarche in various populations surveyed in the last several decades has ranged from 12.0 to 18.5 years. The earliest mean is reported for African-American girls and the oldest for high altitude subsistence populations in Asia. However, it is clear that much of the higher age averages reflect nutritional limitations more than genetic differences and can change within a few generations with a substantial change in diet. The median age of menarche for a population may be an index of the proportion of undernourished girls in the population, and the width of the spread may reflect unevenness of wealth and food distribution in a population.

Genetic influence

Various studies have found direct genetic effects to account for at least 50% of the variation of timing of puberty in well-nourished populations. The genetic association of timing is strongest between mothers and daughters. The specific genes affecting timing are not defined yet. Among the candidates are the androgen and LH receptor genes.

Environmental factors

If genetic factors account for half of the variation of pubertal timing, environment factors are clearly important as well. One of the earliest observed environmental effects is that puberty occurs later in children raised at higher altitudes. The most important of the environmental influences is clearly nutrition, but a number of others have been identified, all which affect timing of female puberty and menarche more clearly than male puberty.

Nutritional influence

Nutritional factors are the strongest and most obvious environmental factors affecting timing of puberty. Girls are especially sensitive to nutritional regulation because they must contribute all of the nutritional support to a growing fetus. Surplus calories (beyond growth and activity requirements) are reflected in the amount of body fat, which signals to the brain the availability of resources for initiation of puberty and fertility.

Much evidence suggests that for most of the last few centuries, nutritional differences accounted for majority of variation of pubertal timing in different populations, and even among social classes in the same population. Recent worldwide increased consumption of animal protein, other changes in nutrition, and increases in childhood fatness have resulted in falling ages of puberty, mainly in those populations with the higher previous ages. In many populations the amount of variation attributable to nutrition is shrinking.

Although available dietary energy (simple calories) is the most important dietary influence on timing of puberty, quality of the diet plays a role as well. Lower protein intakes and higher plant fiber intakes, as occur with typical vegetarian diets, are associated with later onset and slower progression of female puberty.

Studies have shown that calcium deficiency is a cause of late puberty, irregular and painful, cramping during menstruation with excessive blood loss, and lowered immune response to infections in young girls. This could be from a deficient diet or lack of vitamin D from too little sun exposure. This lack of calcium could predispose them to osteoporosis later in life.

Physical activity and exercise

The average level of daily physical activity has also been shown to affect timing of puberty, especially female. A high level of exercise, whether for athletic or body image purposes, or for daily subsistence, reduces energy calories available for reproduction and slows puberty. The exercise effect is often amplified by a lower body fat mass.

Physical illness

Many chronic diseases can delay puberty in both boys and girls. Those that involve chronic inflammation or interfere with nutrition have the strongest effect. In the western world, inflammatory bowel disease and tuberculosis have been notorious for such an effect in the last century, while in areas of the underdeveloped world, chronic parasite infections are widespread.

Environmental chemicals and hormones

There is theoretical concern, and animal evidence, that environmental hormones and chemicals may affect aspects of prenatal or postnatal sexual development in humans. Large amounts of incompletely metabolized estrogens and progestagens from pharmaceutical products are excreted into the sewage systems of large cities, and are sometimes detectable in the environment. Sex steroids are sometimes used in cattle farming but have been banned in chicken meat production for 40 years. Although agricultural laws regulate use to minimize accidental human consumption, the rules are largely self-enforced in the United States. Significant exposure of a child to hormones or other substances that activate estrogen or androgen receptors could produce some or all of the changes of puberty.

Harder to detect as an influence on puberty are the more diffusely distributed environmental chemicals like PCBs (polychlorinated biphenyl), which can bind and trigger estrogen receptors.

More obvious degrees of partial puberty from direct exposure of young children to small but significant amounts of pharmaceutical sex steroids from exposure at home may be detected during medical evaluation for precocious puberty, but mild effects and the other potential exposures outlined above would not.

Stress and social factors

Some of the least understood environmental influences on timing of puberty are social and psychological. In comparison with the effects of genetics, nutrition, and general health, social influences are small, shifting timing by a few months rather than years. Mechanisms of these social effects are unknown, though a variety of physiological processes, including pheromones, have been suggested based on animal research.

The most important part of a child's psychosocial environment is the family, and most of the social influence research has investigated features of family structure and function in relation to earlier or later female puberty. Most of the studies have reported that menarche may occur a few months earlier in girls in high-stress households, whose fathers are absent during their early childhood, who have a stepfather in the home, who are subjected to prolonged sexual abuse in childhood, or who are adopted from a developing country at a young age. Conversely, menarche may be slightly later when a girl grows up in a large family with a biological father present.

More extreme degrees of environmental stress, such as wartime refugee status with threat to physical survival, have been found to be associated with delay of maturation, an effect that may be compounded by dietary inadequacy.

Most of these reported social effects are small and our understanding is incomplete. Most of these "effects" are statistical associations revealed by epidemiologic surveys. Statistical associations are not necessarily causal, and a variety of covariables and alternative explanations can be imagined. Effects of such small size can never be confirmed or refuted for any individual child. Furthermore, interpretations of the data are politically controversial because of the ease with which this type of research can be used for political advocacy. Accusations of bias based on political agenda sometimes accompany scientific criticism.

Another limitation of the social research is that nearly all of it has concerned girls, partly because female puberty requires greater physiologic resources and partly because it involves a unique event (menarche) that makes survey research into female puberty much simpler than male. More detail is provided in the menarche article.

Average timing for American children

Some of the most complete reference data are available for American children and are included here. Average age for first signs of breast development in girls is about 10.5 years. Average age for first signs of testicular enlargement in boys is 11.5 years. See Tables below for approximate average ages and ranges for other milestones of physical development of North American children.

Duration of puberty (time from onset to completion) varies less between children than does the age of onset. Duration of puberty in girls from onset of breast development to cessation of growth is roughly 5 years. Duration of puberty in boys from first testicular enlargement to cessation of growth is about 6 years.

Table 1 provides 3rd, 50th, and 97th percentiles for attainment of selected stages by American girls, based on NCHS data collected in the 1970s and reported in 1985 (Tanner et al., 1985). In these tables, B, PH, and G refer to the Tanner stages of physical puberty: B is breast, PH is pubic hair, and G is genitalia (penis and testes). B1, PH1, and G1 are the prepubertal stages of each of these, while B2, PH2, and G2 are the earliest signs of puberty. B5, PH5, and G5 are adult stages at the end of puberty. The Tanner stage article contains links to fuller explanations of the specific stages. All three tables below express ages as years and months (y and m).

Table 1: Ages of attainment of pubertal stages of American girls
Stages 3rd percentile 50th percentile 97th percentile
B2 8y 10 m 10y 11 m 13y 0 m
B3 9y 10 m 11y 11 m 14y 0 m
B4 10y 6 m 12y 11 m 14y 5 m
PH2 9y 0 m 11y 3 m 13y 6 m
PH3 9y 8 m 11y 11 m 14y 3 m
PH4 10y 5 m 12y 7 m 14y 7 m
Menarche 10y 10 m 12y 9 m 14y 7 m
Peak height velocity 9y 0 m 11y 6 m 14y 0 m

However, a later survey performed in the mid-1990s by a group of American primary pediatric practices with slightly different methods reported both a mildly earlier average onset, greater range, and more importantly, a significant difference between white and African-American girls in the early stages (Table 2) (Herman-Giddens et al.).

Table 2a: 1997 survey of white American girls
Stages 3rd percentile 50th percentile 97th percentile
B2 6y 5 m 10y 0 m 13y 7 m
B3 8y 7 m 11y 4 m 14y 1 m
B4 10y 4 m 12y 9 m 15y 3 m
B5 11y 4 m 14y 6 m 17y 9 m
PH2 7y 2 m 10y 5 m 13y 8 m
PH3 8y 8 m 11y 5 m 14y 2 m
PH4 10y 5 m 14y 7 m 14y 7 m
PH5 10y 10 m 12y 2 m 16y 8 m
Menarche 10y 6 m 12y 10 m 15y 3 m
Peak height velocity 10y 0 m 12y 6 m 14y 0 m
Table 2b: Recent survey of African-American girls
Stages 3rd percentile 50th percentile 97th percentile
B2 5y 0 m 8y 11 m 12y 10 m
B3 7y 7 m 10y 2 m 12y 11 m
PH2 4y 9 m 8y 9