Puberty is 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, blood, skin, hair, breasts, and sex organs. Growth accelerates in the first half of puberty and stops at the completion of puberty. 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'' (derived from the Latin word ''puberatum'' (age of maturity, manhood)) 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, girls typically begin the process of puberty at age 10 or 11; boys at age 12 or 13. Girls usually complete puberty by ages 15–17, while boys usually complete puberty by ages 16–18. Any increase in height beyond the post-pubertal age is uncommon. Girls attain 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.

[[File:Hormons feedback - Sprzężenie zwrotne hormonow.svg|right|thumb|300px|1 Follicle-stimulating hormone - FSH 2 Luteinizing hormone - LH 3 Progesterone 4 Estrogen 5 Hypothalamus 6 Pituitary gland 7 Ovary 8 Pregnancy - hCG (Human chorionic gonadotropin) 9 Testosterone 10 Testicle 11 Incentives 12 Prolactin - PRL]] For boys, an androgen called testosterone is the principal sex hormone. While testosterone produces all boys' 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 on average 2 cm shorter 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, a direct result of the later rise and lower adult male levels of estradiol.

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

Puberty onset

The onset of puberty is associated with high GnRH pulsing, which precedes the rise in sex hormones, LH and FSH. Exogenous GnRH pulses cause the onset of puberty. Brain tumors which increase GnRH output may also lead to premature puberty

The cause of the GnRH rise is unknown. Leptin might be the cause of the GnRH rise. Leptin has receptors in the hypothalamus which synthesizes GnRH. Individuals who are deficient in leptin fail to initiate puberty. The levels of leptin increase with the onset of puberty, and then decline to adult levels when puberty is completed. The rise in GnRH might also be caused by genetics. A study discovered that a mutation in genes encoding both Neurokinin B as well as the Neurokinin B receptor can alter the timing of puberty. The researchers hypothesized that Neurokinin B might play a role in regulating the secretion of Kisspeptin, a compound responsible for triggering direct release of GnRH as well as indirect release of LH and FSH.

Physical changes in boys

Testicular size, function, and fertility

In boys, testicular enlargement is the first physical manifestation of puberty (and is termed gonadarche). Testes in prepubertal boys change little in size from about 1 year of age to the onset of puberty, averaging about 2–3 cm in length and about 1.5–2 cm in width. Testicular size continues to increase throughout puberty, reaching maximal adult size about 6 years after the onset of puberty. After the boy's testicles have enlarged and developed for about one year, the length and then the breadth of the shaft of the penis will increase and the glans penis and corpora cavernosa will also start to enlarge to adult proportions. While 18–20 cm³ is an average adult size, there is wide variation in testicular size in the normal population.

The testes have two primary functions: to produce hormones and to produce sperm. The Leydig cells produce testosterone, which in turn produces most of the male pubertal changes. Most of the increasing bulk of testicular tissue is spermatogenic tissue (primarily Sertoli and Leydig cells). Sperm can be detected in the morning urine of most boys after the first year of pubertal changes, and occasionally earlier. On average, potential fertility in boys is reached at 13 years old, but full fertility will not be gained until 14–16 years of age.

During puberty, a male's scrotum will become larger and begin to dangle or hang below the body as opposed to being up tight, to accommodate the production of sperm whereby the testicles need a certain temperature to be fertile.

Foreskin retraction

During puberty, if not before, the tip and opening of a boy's foreskin becomes wider, progressively allowing for retraction down the shaft of the penis and behind the glans, which ultimately should be possible without pain or difficulty. The membrane that bonds the inner surface of the foreskin with the glans disintegrates and releases the foreskin to separate from the glans. The foreskin then gradually becomes retractable.

Research in 1968 by Danish pediatrician Jakob Øster found that with the onset and continuation of puberty, the proportion of boys able to pull back their foreskins increased. At ages 12–13, Øster found that only 60% of boys were able to retract their foreskins; this increased to 85% at ages 14–15, and 95% by 16–17 years old. He also found that only 1% of those unable to fully retract suffered from phimosis at ages 14–17, the remainder were partially able to. The findings were supported by further research by Japanese doctor Hiroyuki Kayaba ''et al'' in 1996, on a sample of over 600 boys, and in 2004 Ishikawa and Kawakita found that by age 15, 77% of their sample of boys could retract their foreskins.

Once a boy is able to retract his foreskin, penile hygiene should become an important feature of his routine body care. Although the American Academy of Pediatrics states there is "little evidence to affirm the association between circumcision status and optimal penile hygiene", various studies suggest that uncircumcised boys are educated about the role of hygiene, including retracting the foreskin while urinating and rinsing underneath it and around the glans at each bathing opportunity. Regular washing under the foreskin was found, in a 1986 study by Krueger and Osborn, to reduce the risk of numerous penile disorders.

Pubic hair

Pubic hair often appears on a boy shortly after the genitalia begin to grow. 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 many to count. By stage 4, the pubic hairs densely fill the "pubic triangle." Stage 5 refers to the 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 that respond to androgens may develop androgenic hair. The usual sequence is: underarm (axillary) hair, perianal hair, upper lip hair, sideburn (preauricular) hair, periareolar hair, and the beard area. As with most human biological processes, this specific order may vary among some individuals. 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 racial groups. Facial hair is often present in late adolescence, but may not appear until significantly later. Facial hair will continue to get coarser, darker and thicker for another 2–4 years after puberty. Some men do not develop full facial hair for up to 10 years after the completion of puberty. Chest hair may appear during puberty or years after. Not all men have chest hair.

Voice change and Adam's apple

Under the influence of androgens, the voice box, or larynx, grows in both sexes. This growth is far more prominent in boys, causing the male voice to drop and deepen, sometimes abruptly but rarely "over night," about one octave, because the longer and thicker vocal folds have a lower fundamental frequency. Before puberty, the larynx of boys and girls is about equally small. Occasionally, voice change is accompanied by unsteadiness of vocalization in the early stages of untrained voices. Most of the voice change happens during stage 3-4 of male puberty around the time of peak growth. Full adult pitch is attained at an average age of 15 years. It usually precedes the development of significant facial hair by several months to years. In men, the Laryngeal grows in size.

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 boys are 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.

Often, the fat pads of the male breast tissue and the male nipples will develop during puberty; sometimes, especially in one breast, this becomes more apparent and is termed gynecomastia. It is usually not a permanent phenomenon.

Body odor and 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. Acne can not be prevented or diminished easily, but it typically fully diminishes at the end of puberty. However, it is not unusual for a fully grown adult to suffer the occasional bout of acne, though it is normally less severe than in adolescents. Some may desire using prescription topical creams or ointments to keep acne from getting worse, or even oral medication, due to the fact that acne is emotionally difficult and can cause scarring.

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 of one or both breasts, occurring on average at about 10.5 years of age. 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.

Pubic hair

Pubic hair is often the second noticeable change in puberty, usually within a few months of thelarche. It is referred to as pubarche. The pubic hairs are usually visible first along the labia. The first few hairs are described as Tanner stage 2. 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.

Vagina, uterus, ovaries

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

Menstruation and fertility

The first menstrual bleeding is referred to as menarche, and typically occurs about two years after thelarche. The average age of menarche in girls is 11.75 years. The time between menstrual periods (menses) is not always regular in the first two years after menarche. Ovulation is necessary for fertility, but may or may not accompany the earliest menses. In postmenarchal girls, about 80% of the cycles were anovulatory in the first year after menarche, 50% in the third year and 10% in the sixth year. Initiation of ovulation after menarche is not inevitable. A high proportion of girls with continued irregularity in the menstrual cycle several years from menarche will continue to have prolonged irregularity and anovulation, and are at higher risk for reduced fertility. Nubility is used to designate achievement of fertility.

Body shape, fat distribution, and body composition

During this period, also in response to rising levels of estrogen, the lower half of the pelvis and thus hips widen (providing a larger birth canal). 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. On average, at 10 years, girls have 6% more body fat than boys.

Body odor 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 one or more years. Another androgen effect is increased secretion of oil (sebum) from the skin. This change increases the susceptibility to acne, a skin condition that is characteristic of puberty. Acne varies greatly in its severity.

Variations

Timing of the onset of puberty

The definition of the onset of puberty depends on perspective (e.g., hormonal versus physical) and purpose (establishing population normal standards, clinical care of early or late pubescent individuals, etc.). The most commonly used definition of the onset of puberty is physical changes to a person's body. These physical changes are the first visible signs of neural, hormonal, and gonadal function changes.

The age at which puberty begins varies between individuals; usually, puberty begins between 10 and 13 years of age. The age at which puberty begins is affected by both genetic factors and by environmental factors such as nutritional state and social circumstances. An example of social circumstances is the Vandenbergh effect; a juvenile female who has significant interaction with adult males will enter puberty earlier than juvenile females who are not socially overexposed to adult males.

The average age at which puberty begins may be affected by race as well. For example, the average age of menarche in various populations surveyed has ranged from 12 to 18 years. The earliest average onset of puberty is for African-American girls and the latest average onset for high altitude subsistence populations in Asia. However, 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.

Researchers have identified an earlier age of the onset of puberty. However, they have based their conclusions on a comparison of data from 1999 with data from 1969. In the earlier example, the sample population was based on a small sample of white girls (200, from Britain). The later study identified as puberty as occurring in 48% of African-American girls by age nine, and 12% of white girls by that age.

Historical shift

The average age at which the onset of puberty occurs has dropped significantly since the 1840s. This was dubbed 'the secular trend' by J.M. Tanner. In every decade from 1840 to 1950 there was a drop of four months in the average age of menarche among Western European females. In Norway, girls born in 1840 had their menarche at an average age of 17 years. In France the average in 1840 was 15.3 years. In England the average in 1840 was 16.5 years. In Japan the decline happened later and was then more rapid: from 1945 to 1975 in Japan there was a drop of 11 months per decade.

A 2006 study in Denmark found that puberty, as evidenced by breast development, started at an average age of 9 years and 10 months, a year earlier than when a similar study was done in 1991. Scientists believe the phenomenon could be linked to obesity or exposure to chemicals in the food chain, and is putting girls at greater long-term risk of breast cancer.

Genetic influence and environmental factors

Various studies have found direct genetic effects to account for at least 46% 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 yet known. Among the candidates is an androgen receptor gene.

Researchers have hypothesized that early puberty onset may be caused by certain hair care products containing estrogen or placenta, and by certain chemicals, namely phthalates, which are used in many cosmetics, toys, and plastic food containers.

If genetic factors account for half of the variation of pubertal timing, environment factors are clearly important as well. One of the first 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.

Hormones and steroids

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.

Bisphenol A (BPA) is a chemical used to make plastics, and is frequently used to make baby bottles, water bottles, sports equipment, medical devices, and as a coating in food and beverage cans. Scientists are concerned about BPA's behavioral effects on fetuses, infants, and children at current exposure levels because it can affect the prostate gland, mammary gland, and lead to early puberty in girls. BPA mimics and interferes with the action of estrogen-an important reproduction and development regulator. It leaches out of plastic into liquids and foods, and the Centers for Disease Control and Prevention (CDC) found measurable amounts of BPA in the bodies of more than 90 percent of the U.S. population studied. The highest estimated daily intakes of BPA occur in infants and children. Many plastic baby bottles contain BPA, and BPA is more likely to leach out of plastic when its temperature is increased, as when one warms a baby bottle or warms up food in the microwave.

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 obesity 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 dietary fiber intakes, as occur with typical vegetarian diets, are associated with later onset and slower progression of female puberty.

Obesity influence and exercise

Scientific researchers have linked early obesity with an earlier onset of puberty in girls. They have cited obesity as a cause of breast development before nine years and menarche before twelve years. Early puberty in girls can be a harbinger of later health problems.

The average level of daily physical activity has also been shown to affect timing of puberty, especially in females. 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 and cholesterol.

Physical and mental illness

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.

Mental illnesses occur in puberty. The brain undergoes significant development by hormones which can contribute to mood disorders such as Major depressive disorder, bipolar disorder, dysthymia and schizophrenia. Girls aged between 15 and 19 make up 40% of anorexia nervosa cases.

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.

Variations of sequence

The sequence of events of pubertal development can occasionally vary. For example, in about 15% of boys and girls, pubarche (the first pubic hairs) can precede, respectively, gonadarche and thelarche by a few months. Rarely, menarche can occur before other signs of puberty in a few girls. These variations deserve medical evaluation because they can occasionally signal a disease.

Conclusion

In a general sense, the conclusion of puberty is reproductive maturity. Criteria for defining the conclusion may differ for different purposes: attainment of the ability to reproduce, achievement of maximal adult height, maximal gonadal size, or adult sex hormone levels. Maximal adult height is achieved at an average age of 15 years for an average girl and 18 years for an average boy. Potential fertility (sometimes termed ''nubility'') usually precedes completion of growth by 1–2 years in girls and 3–4 years in boys. Stage 5 typically represents maximal gonadal growth and adult hormone levels.

Neurohormonal process

The endocrine reproductive system consists of the hypothalamus, the pituitary, the gonads, and the adrenal glands, with input and regulation from many other body systems. True puberty is often termed "central puberty" because it begins as a process of the central nervous system. A simple description of hormonal puberty is as follows:

#The brain's hypothalamus begins to release pulses of GnRH. #Cells in the anterior pituitary respond by secreting LH and FSH into the circulation. #The ovaries or testes respond to the rising amounts of LH and FSH by growing and beginning to produce estradiol and testosterone. #Rising levels of estradiol and testosterone produce the body changes of female and male puberty.

The onset of this neurohormonal process may precede the first visible body changes by 1–2 years.

Components of the endocrine reproductive system

The arcuate nucleus of the hypothalamus is the driver of the reproductive system. It has neurons which generate and release pulses of GnRH into the portal venous system of the pituitary gland. The arcuate nucleus is affected and controlled by neuronal input from other areas of the brain and hormonal input from the gonads, adipose tissue and a variety of other systems.

The pituitary gland responds to the pulsed GnRH signals by releasing LH and FSH into the blood of the general circulation, also in a pulsatile pattern.

The gonads (testes and ovaries) respond to rising levels of LH and FSH by producing the steroid sex hormones, testosterone and estrogen.

The adrenal glands are a second source for steroid hormones. Adrenal maturation, termed adrenarche, typically precedes gonadarche in mid-childhood.

Major hormones

Neurokinin B (a tachykinin peptide) and kisspeptin (a neuropeptide), both present in the same hypothalamic neurons, are critical parts of the control system that switches on the release of GnRH at the start of puberty.

GnRH (gonadotropin-releasing hormone) is a peptide hormone released from the hypothalamus which stimulates gonadotrope cells of the anterior pituitary.

LH (luteinizing hormone) is a larger protein hormone secreted into the general circulation by gonadotrope cells of the anterior pituitary gland. The main target cells of LH are the Leydig cells of testes and the theca cells of the ovaries. LH secretion changes more dramatically with the initiation of puberty than FSH, as LH levels increase about 25-fold with the onset of puberty, compared with the 2.5-fold increase of FSH.

FSH (follicle stimulating hormone) is another protein hormone secreted into the general circulation by the gonadotrope cells of the anterior pituitary. The main target cells of FSH are the ovarian follicles and the Sertoli cells and spermatogenic tissue of the testes.

Testosterone is a steroid hormone produced primarily by the Leydig cells of the testes, and in lesser amounts by the theca cells of the ovaries and the adrenal cortex. Testosterone is the primary mammalian androgen and the "original" anabolic steroid. It acts on androgen receptors in responsive tissue throughout the body.

Estradiol is a steroid hormone produced by aromatization of testosterone. Estradiol is the principal human estrogen and acts on estrogen receptors throughout the body. The largest amounts of estradiol are produced by the granulosa cells of the ovaries, but lesser amounts are derived from testicular and adrenal testosterone.

Adrenal androgens are steroids produced by the zona reticulosa of the adrenal cortex in both sexes. The major adrenal androgens are dehydroepiandrosterone, androstenedione (which are precursors of testosterone), and dehydroepiandrosterone sulfate which is present in large amounts in the blood. Adrenal androgens contribute to the androgenic events of early puberty in girls.

IGF1 (insulin-like growth factor 1) rises substantially during puberty in response to rising levels of growth hormone and may be the principal mediator of the pubertal growth spurt.

Leptin is a protein hormone produced by adipose tissue. Its primary target organ is the hypothalamus. The leptin level seems to provide the brain a rough indicator of adipose mass for purposes of regulation of appetite and energy metabolism. It also plays a permissive role in female puberty, which usually will not proceed until an adequate body mass has been achieved.

Endocrine perspective

The endocrine reproductive system becomes functional by the end of the first trimester of fetal life. The testes and ovaries become briefly inactive around the time of birth but resume hormonal activity until several months after birth, when incompletely understood mechanisms in the brain begin to suppress the activity of the arcuate nucleus. This has been referred to as maturation of the prepubertal "gonadostat," which becomes sensitive to negative feedback by sex steroids. The period of hormonal activity until several months after birth, followed by suppression of activity, may correspond to the period of infant sexuality, followed by a latency stage, which Sigmund Freud described.

Gonadotropin and sex steroid levels fall to low levels (nearly undetectable by current clinical assays) for approximately another 8 to 10 years of childhood. Evidence is accumulating that the reproductive system is not totally inactive during the childhood years. Subtle increases in gonadotropin pulses occur, and ovarian follicles surrounding germ cells (future eggs) double in number.

Normal puberty is initiated in the hypothalamus, with de-inhibition of the pulse generator in the arcuate nucleus. This inhibition of the arcuate nucleus is an ongoing active suppression by other areas of the brain. The signal and mechanism releasing the arcuate nucleus from inhibition have been the subject of investigation for decades and remain incompletely understood. Leptin levels rise throughout childhood and play a part in allowing the arcuate nucleus to resume operation. If the childhood inhibition of the arcuate nucleus is interrupted prematurely by injury to the brain, it may resume pulsatile gonadotropin release and puberty will begin at an early age.

Neurons of the arcuate nucleus secrete gonadotropin releasing hormone (GnRH) into the blood of the pituitary portal system. An American physiologist, Ernst Knobil, found that the GnRH signals from the hypothalamus induce pulsed secretion of LH (and to a lesser degree, FSH) at roughly 1-2 hour intervals. The LH pulses are the consequence of pulsatile GnRH secretion by the arcuate nucleus that, in turn, is the result of an oscillator or signal generator in the central nervous system ("GnRH pulse generator"). In the years preceding physical puberty, Robert M. Boyar discovered that the gonadotropin pulses occur only during sleep, but as puberty progresses they can be detected during the day. By the end of puberty, there is little day-night difference in the amplitude and frequency of gonadotropin pulses.

Some investigators have attributed the onset of puberty to a resonance of oscillators in the brain. By this mechanism, the gonadotropin pulses that occur primarily at night just before puberty represent beats.

An array of "autoamplification processes" increases the production of all of the pubertal hormones of the hypothalamus, pituitary, and gonads.

Regulation of adrenarche and its relationship to maturation of the hypothalamic-gonadal axis is not fully understood, and some evidence suggests it is a parallel but largely independent process coincident with or even preceding central puberty. Rising levels of adrenal androgens (termed adrenarche) can usually be detected between 6 and 11 years of age, even before the increasing gonadotropin pulses of hypothalamic puberty. Adrenal androgens contribute to the development of pubic hair (pubarche), adult body odor, and other androgenic changes in both sexes. The primary clinical significance of the distinction between adrenarche and gonadarche is that pubic hair and body odor changes by themselves do not prove that central puberty is underway for an individual child.

Hormonal changes in boys

Early stages of male hypothalamic maturation seem to be very similar to the early stages of female puberty, though occurring about 1–2 years later.

LH stimulates the Leydig cells of the testes to make testosterone and blood levels begin to rise. For much of puberty, nighttime levels of testosterone are higher than daytime. Regularity of frequency and amplitude of gonadotropin pulses seems to be less necessary for progression of male than female puberty.

However, a significant portion of testosterone in adolescent boys is converted to estradiol. Estradiol mediates the growth spurt, bone maturation, and epiphyseal closure in boys just as in girls. Estradiol also induces at least modest development of breast tissue (gynecomastia) in a large proportion of boys. Boys who develop mild gynecomastia or even developing swellings under nipples during puberty are told the effects are temporary in some male teenagers due to high levels of estradiol.

Another hormonal change in males takes place during the teenage years for most young men. At this point in a males life the testosterone levels slowly rise, and most of the effects are mediated through the androgen receptors by way of conversion dihydrotestosterone in target organs (especially that of the bowels).

Hormonal changes in girls

As the amplitude of LH pulses increases, the theca cells of the ovaries begin to produce testosterone and smaller amounts of progesterone. Much of the testosterone moves into nearby cells called granulosa cells. Smaller increases of FSH induce an increase in the aromatase activity of these granulosa cells, which converts most of the testosterone to estradiol for secretion into the circulation.

Rising levels of estradiol produce the characteristic estrogenic body changes of female puberty: growth spurt, acceleration of bone maturation and closure, breast growth, increased fat composition, growth of the uterus, increased thickness of the endometrium and the vaginal mucosa, and widening of the lower pelvis.

As the estradiol levels gradually rise and the other autoamplification processes occur, a point of maturation is reached when the feedback sensitivity of the hypothalamic "gonadostat" becomes positive. This attainment of positive feedback is the hallmark of female sexual maturity, as it allows the mid cycle LH surge necessary for ovulation.

Levels of adrenal androgens and testosterone also increase during puberty, producing the typical androgenic changes of female puberty: pubic hair, other androgenic hair as outlined above, body odor, acne.

Growth hormone levels rise steadily throughout puberty. IGF1 levels rise and then decline as puberty ends. Growth finishes and adult height is attained as the estradiol levels complete closure of the epiphyses.

Stages

adrenarche (approximately age 7)

gonadarche (approximately age 8)

thelarche (approximately age 11 in females)

pubarche (approximately age 12)

menarche (approximately age 12.5 in females)

spermarche (in males)

See also

Adolescent sexuality

Child sexuality

Delayed puberty

Eunuch

Hebephilia

Precocious puberty

Secondary sex characteristic

Puberphonia

References

Further reading

Colburn, T., Dumanoski, D. and Myers, J.P. Our Stolen Future, 1996, Plume: New York.

Ducros, A. and Pasquet, P. "Evolution de l'âge d'apparition des premières règles (ménarche) en France". ''Biométrie Humaine'' (1978), 13, 35–43.

Newer data suggesting that lower age thresholds for evaluation should be used.

Plant TM, Lee PA, eds. ''The Neurobiology of Puberty''. Bristol: Society for Endocrinology, 1995. Proceedings of the latest (4th) International Conference on the Control of the Onset of Puberty, containing summaries of current theories of physiological control, as well as GnRH analog treatment.

Highly useful growth charts with integrated standards for stages of puberty.

Sizonenko, PC. Role of sex steroids during development—integration. in Bourguignon, Jean Pierre & Tony M. Plant. The Onset of Puberty in Perspective: Proceedings of the 5th International Conference on the Control of the Onset of Puberty, Held in Liège, Belgium, 26–28 September 1999. Elsevier. Amsterdam & New York 2000. ISBN 0444502963. pp 299–306.

External links

Support for teens

NIH guide to puberty and adolescence

Growing Up Sexually: A World Atlas

Pictures and detailed information about breast development during puberty

Research shows how evolution explains age of puberty, ''ScienceDaily'', December 1, 2005.

Puberty in girls: interactive animation of Tanner stages

Puberty in boys: interactive animation of Tanner stages

Category:Adolescence Category:Human development Category:Sexuality and age

als:Pubertät ar:بلوغ bn:বয়ঃসন্ধি bar:Pubertät bo:ལང་ཚོ་དར་བབས། br:Kaezouregezh bg:Пубертет ca:Pubertat cs:Puberta cy:Glasoed da:Pubertet de:Pubertät et:Puberteet es:Pubertad eo:Pubereco eu:Nerabezaro fa:بلوغ جنسی fr:Puberté gl:Puberdade ko:사춘기 hi:यौवनारम्भ hr:Pubertet id:Pubertas it:Pubertà he:התבגרות מינית ka:პუბერტატი sw:Ubalehe la:Pubertas lv:Pubertāte lt:Lytinė branda hu:Kamaszkor mk:Пубертет ms:Baligh nl:Puberteit ja:思春期 no:Pubertet nn:Pubertet nds:Pubertät pl:Pokwitanie pt:Puberdade ro:Pubertate ru:Половое созревание scn:Pubbirtati si:ද්විතියික ලිංගික ලක්ෂණ simple:Puberty sk:Puberta sl:Puberteta sr:Пубертет sh:Pubertet fi:Murrosikä sv:Pubertet ta:பூப்பு tr:Ergenlik dönemi uk:Статеве дозрівання vi:Dậy thì zh:青春期

name	Justin Bieber
background	solo_singer
birth name	Justin Drew Bieber
birth date	March 01, 1994
birth place	London, Ontario, Canada
origin	Stratford, Ontario, Canada
instrument	Vocals, guitar, piano, percussion, trumpet
genre	Pop, R&B;, teen pop
occupation	Singer, musician, actor
years active	2009–present
label	Island, RBMG
associated acts	Usher
website	justinbiebermusic.com }}

Justin Drew Bieber ( , born March 1, 1994) is a Canadian pop/R&B; singer, songwriter and actor. Bieber was discovered in 2008 by Scooter Braun, who came across Bieber's videos on YouTube and later became his manager. Braun arranged for him to meet with Usher in Atlanta, Georgia, and Bieber was soon signed to Raymond Braun Media Group (RBMG), a joint venture between Braun and Usher, and then to a recording contract with Island Records offered by L.A. Reid. Bieber's debut single, "One Time", was released in 2009 and peaked in the top ten in Canada and charted in the top thirty in several international markets. His debut album, the seven-track EP ''My World'', followed in November 2009, and was soon certified platinum in the United States. He became the first artist to have seven songs from a debut album chart on the ''Billboard'' Hot 100.

Bieber's first full-length studio album, ''My World 2.0'', was released in March 2010. It debuted at number one or within the top ten in several countries and was certified platinum in the United States. It was preceded by the worldwide top-ten single, "Baby". The music video of "Baby" is currently ranked as the most viewed and most discussed YouTube video. Bieber followed-up the release of his debut album with his first headlining tour, the My World Tour, the remix albums ''My Worlds Acoustic'' and ''Never Say Never – The Remixes'', and the 3D biopic-concert film ''Justin Bieber: Never Say Never'' – which had an opening weekend gross that nearly matched the record for the biggest opening weekend for a concert-film. Bieber released his second studio album, ''Under the Mistletoe'' in November 2011, which debuted at number one on the ''Billboard'' 200. Bieber has received numerous awards, including Artist of the Year at the 2010 American Music Awards — and has been nominated for numerous awards, including Best New Artist and Best Pop Vocal Album at the 53rd Grammy Awards.

Life and career

1994–2007: Childhood and youth

Bieber was born on March 1, 1994, in London, Ontario, and was raised in Stratford, Ontario. Bieber's mother, Patricia Lynn "Pattie" Mallette, was 18 years old when she became pregnant with her son. Mallette, originally from Stratford, raised her son with the help of her parents, Bruce and Diane. Mallette worked a series of low-paying office jobs, raising Bieber as a single mother in low-income housing. Bieber has maintained contact with his father, Jeremy Jack Bieber, who married another woman and had two children. Bieber's paternal great-grandfather was a German immigrant to Canada. His mother's ancestry is French Canadian. Bieber attended French immersion school at Stratford school Jean Sauve.

During his childhood, Bieber was interested in hockey, soccer, and chess; he often kept his musical aspirations to himself. As he grew up, Bieber taught himself to play the piano, drums, guitar, and trumpet. In early 2007, when he was twelve, Bieber sang Ne-Yo's "So Sick" for a local singing competition in Stratford and placed second. Mallette posted a video of the performance on YouTube for their family and friends to see. She continued to upload videos of Bieber singing covers of various R&B; songs, and Bieber's popularity on the site grew. Chris Hicks, Bieber's A&R; at Island/Def Jam, explained the young artist's huge online following to HitQuarters by saying:

"He was doing something different. He was an attractive white kid singing very soulful R&B; hits. That set him apart immediately from anyone in his range because no one was covering or singing these kind of records. But equally important was that you believed in these songs – it was real. And you wanted to hear more."

2008–09: Discovery and ''My World''

While searching for videos of a different singer, Scooter Braun, a former marketing executive of So So Def, clicked on one of Bieber's 2007 videos by accident. Impressed, Braun tracked down the theater Bieber was performing in, located Bieber's school, and finally contacted Mallette. Mallette was reluctant because of Braun's Jewish religion; she remembered praying, "God, I gave him to you. You could send me a Christian man, a Christian label! ... you don’t want this Jewish kid to be Justin’s man, do you?" However, after praying with her church elders and receiving their encouragement, she permitted Braun to fly Bieber, then 13, to Atlanta, Georgia, to record demo tapes. A week after arriving, Bieber sang for R&B; singer/songwriter Usher. Bieber was soon signed to Raymond Braun Media Group (RBMG), a joint venture between Braun and Usher. Justin Timberlake was also reportedly in the running to sign Bieber, but lost the bidding war to Usher. Usher then sought assistance in finding a label home for the artist from then manager Chris Hicks, who helped engineer an audition with his contact Antonio L.A. Reid of Island Def Jam Music Group. Reid signed Bieber to Island Records in October 2008 (resulting in a joint venture between RBMG and Island Records) and appointed Hicks as executive Vice-President of Def Jam where he would be able manage Bieber's career at the label. At that point, Bieber and his mother moved to Atlanta temporarily, also the home of Usher and Braun, to record and get counseling from Braun. Braun became Bieber's manager.

Bieber's first single, "One Time", was released to radio while Bieber was still recording his debut album. The song reached number 12 on the Canadian Hot 100 during its first week of release in July 2009, and later peaked at number 17 on the Billboard Hot 100. During fall 2009 it had success in international markets. The song was certified Platinum in Canada and the US and Gold in Australia and New Zealand. Bieber's first release, an extended play entitled ''My World'', was released on November 17, 2009. The album's second single, "One Less Lonely Girl", and two promo singles, "Love Me", and "Favorite Girl", were released exclusively on the iTunes store and charted within the top forty of the Billboard Hot 100. "One Less Lonely Girl" was later also released to radio and peaked within the top fifteen in Canada and the US, being certified Gold in the latter. ''My World'' was eventually certified Platinum in the US and Double Platinum in both Canada and the UK. To promote the album, Bieber performed on several live shows such as mtvU's VMA 09 Tour, European program ''The Dome'', YTV's ''The Next Star'', ''The Today Show'', ''The Wendy Williams Show'', ''Lopez Tonight'', ''The Ellen DeGeneres Show'', ''It's On with Alexa Chung'', ''Good Morning America'', ''Chelsea Lately'', and BET's ''106 & Park'' with Rihanna. Bieber also guest starred in an episode of ''True Jackson, VP'' in late 2009.

Bieber performed Stevie Wonder's "Someday at Christmas" for U.S. President Barack Obama and first lady Michelle Obama at the White House for ''Christmas in Washington'', which was broadcast on December 20, 2009, on U.S. television broadcaster TNT. Bieber was also one of the performers at Dick Clark's New Year's Rockin' Eve with Ryan Seacrest on December 31, 2009. Bieber was a presenter at the 52nd Grammy Awards on January 31, 2010. He was invited to be a vocalist for the remake of We Are The World (a song written by Michael Jackson and Lionel Richie) for its 25th anniversary to benefit Haiti after the earthquake. Bieber sings the opening line, which was sung by Lionel Richie in the original version. On March 12, 2010, a version of K'naan's "Wavin' Flag" recorded by a collective of Canadian musicians known as Young Artists for Haiti was released. Bieber is featured in the song, performing the closing lines.

2010: ''My World 2.0'' and continued success

"Baby", the lead single from his debut album, ''My World 2.0'', which features Ludacris, was released in January 2010 and became his biggest hit thus far, charting at number five in the U.S. and reaching the top ten in seven other countries. Two promo singles "Never Let You Go", and "U Smile" were top thirty hits on the U.S. Hot 100, and top twenty hits in Canada. According to review aggregator Metacritic, the album has received "generally favorable reviews". It debuted at number one on the U.S. ''Billboard'' 200, making Bieber the youngest solo male act to top the chart since Stevie Wonder in 1963. ''My World 2.0'' also debuted at number one on the Canadian Albums Chart, Irish Albums Chart, and Australian Albums Chart, and the New Zealand Albums Chart and reached the top ten of fifteen other countries. To promote the album, Bieber appeared on several live programs including ''The View'', the 2010 Kids Choice Awards, ''Nightline'', ''The Late Show with David Letterman'', ''The Dome'' and ''106 and Park''. Bieber collaborated with Sean Kingston on his single "Eenie Meenie" which also appeared on Bieber's debut album. The song reached the top ten in the United Kingdom and Australia, and the top-twenty of most other markets. thumb|left|Bieber performing at the Conseco Fieldhouse, in August 2010 On April 10, 2010, Bieber was the musical guest on ''Saturday Night Live''. On July 4, 2010, Bieber performed at the Macy's Fourth of July Fireworks Spectacular in New York City. The second single from ''My World 2.0'', "Somebody to Love", was released in April 2010, and a remix was released featuring Bieber's mentor Usher. The single reached number ten in Canada, number fifteen in the United States, and the top twenty in multiple international countries.

On June 23, 2010, Bieber went on his first official headlining tour, the My World Tour, starting in Hartford, Connecticut, to promote ''My World'' and ''My World 2.0''. In July 2010, it was reported that Bieber was the most searched for celebrity on the Internet. That same month his music video, "Baby", surpassed Lady Gaga's "Bad Romance" to become the most viewed, and most disliked YouTube video ever. In September 2010, it was reported that Bieber accounted for three percent of all traffic on Twitter, according to an employee of the social-networking site.

Bieber began recording his second album in July 2010 in New York City. At this point, because of puberty, his voice was deeper than it was when he recorded his first album. In April 2010, the singer discussing his vocals remarked, "It cracks. Like every teenage boy, I'm dealing with it and I have the best vocal coach in the world. [...] Some of the notes I hit on "Baby" I can't hit anymore. We have to lower the key when I sing live." British singer/songwriter Taio Cruz confirmed in July 2010 that he is writing songs for Bieber's next album. Hip hop producer Dr. Dre produced two songs with Bieber in July 2010 but it is unknown if they were made for the album, which is currently due for a 2011 release. Bieber guest-starred in the season premiere of the CBS crime drama ''CSI: Crime Scene Investigation'', aired on September 23, 2010. He played a "troubled teen who is faced with a difficult decision regarding his only brother", who is also a serial bomber. Bieber was also in a subsequent episode which aired on February 17, 2011, in which his character is killed. Bieber performed a medley of "U Smile", "Baby", and "Somebody to Love" and briefly played the drums at the 2010 MTV Video Music Awards on September 12, 2010. Bieber announced in October 2010 that he would release an acoustic album, called ''My Worlds Acoustic''. It was released on Black Friday in the United States and featured acoustic versions of songs from his previous albums, and accompanied the release of a completely new song titled "Pray".

2011–present: ''Never Say Never'' film, ''Under the Mistletoe'' and ''Believe''

A 3-D part-biopic, part-concert film starring Bieber entitled ''Justin Bieber: Never Say Never'', was released on February 11, 2011, directed by ''Step Up 3D'' director Jon Chu. It topped the box office with an estimated grossing of $12.4 million on its opening day from 3,105 theaters. It grossed $30.3 million for the weekend and was narrowly beaten by the romantic comedy ''Just Go With It'', which grossed $31 million. ''Never Say Never'' is said to have exceeded industry expectations, nearly matching the $31.1 million grossed by Miley Cyrus's 2008 3-D concert film, Hannah Montana & Miley Cyrus: Best of Both Worlds Concert, which holds the record for the top debut for a music-documentary. The film is accompanied by his second remix album, ''Never Say Never – The Remixes'', released February 14, 2011, and features remixes of songs from his debut album, with guest appearances from Miley Cyrus, Chris Brown, and Kanye West, among others.

On February 27, 2011, Bieber attended the 2011 Vanity Fair Oscar Party with American actress and singer Selena Gomez, confirming several months of media speculation about a romantic relationship between the pair.

In June 2011, Bieber was ranked number 2 on the Forbes list of Best-Paid Celebrities under 30. He is the youngest star and 1 of 7 musicians on the list raking in with $53 million earned in a 12 month period. On November 1, 2011, Bieber released ''Under the Mistletoe'', his second studio album. It debuted at number one on the ''Billboard'' 200, selling 210,000 copies in its first week of release. Bieber is currently recording his third studio album entitled ''Believe''. Kanye West and Drake are confirmed to be featured on the album.

Image

''The Observer'' newspaper in the UK published a report indicating that Justin Bieber is more influential in the social networking sphere than Barack Obama or The Dalai Lama. According to Jan Hoffman of ''The New York Times'', part of Bieber's appeal stems from his YouTube channel. Long before he released his EP, ''My World'', in mid-November, the YouTube videos attracted millions of views. Braun recognized the appeal. Prior to flying him to Atlanta, Braun wanted to "build him up more on YouTube first" and had Bieber record more home videos for the channel. "I said: 'Justin, sing like there’s no one in the room. But let's not use expensive cameras.' We'll give it to kids, let them do the work, so that they feel like it's theirs", recalled Braun. Bieber continues to upload videos to the same channel and has opened a Twitter account, from which he interacts with fans regularly; his account was reported in November 2010 to have over 6 million followers. Since then he has been consistently gaining followers at an average of 24,000 per day. The accounts also serve marketing purposes; for example, Bieber's music video for "One Time" only began selling quickly after it was uploaded to YouTube. Usher comments that while he and Bieber were both signed at the same age, "I had the chance to ramp up my success, where this has happened to Bieber abruptly." As a result, Usher, Braun, Bieber's bodyguard Kenny, and other adults surrounding Bieber constantly coach him on handling fame and his public image. After signing Bieber, Usher appointed one of his former assistants, Ryan Good, to be Bieber's road manager and stylist. Good, once nicknamed Bieber's "swagger coach", created a "streetwise look" for the singer which consisted of baseball caps, hoodies, dog chains and flashy sneakers. Amy Kaufman of ''The Los Angeles Times'' comments, "Though a product of a middle-class suburban upbringing in Stratford, Ontario, Bieber's manner of dress and speech ("Wassup man, how you doin'?" or "It's like, you know, whateva' ") suggest he's mimicking his favorite rappers."

Bieber is often featured in teen magazines such as ''Tiger Beat'', and has been labeled as a "teen hearthrob". Bieber has released a collection of nail varnishes to raise awareness for charity. Wax statues of Bieber are on display at Madame Tussauds wax museums in New York, Amsterdam and London. His change of hairstyle in 2010, and the consequent alterations to Bieber products, led to it being called 'the most expensive musical haircut of all time; one company spent $100,000 to fix its dolls for the 2011 Christmas season.

Bieber has been criticized for looking and sounding younger than his age, his teen-pop music, image, and frequent media attention. He has been a frequent target of Internet bloggers and message board posters, notably by users of Internet message board 4chan and users of YouTube. Nick Collins of ''The Daily Telegraph'' speculated that "Bieber's character also appears to strike a particularly sour note with his Internet critics, with many remarks commenting on his youthful appearance, his teen-pop songs, his image as a heart-throb to young teenage girls and his manner of speech".

Personal views

Bieber is a Christian, and said he has a relationship with Jesus, talks to him and that "he's the reason I'm here".

Bieber's comments in a February 2011 profile in ''Rolling Stone'' sparked controversy. Asked whether a person should wait until marriage to have sex, Bieber responded, "I don't think you should have sex with anyone unless you love them." Asked about his opinion on abortion, Bieber said he does not "believe in abortion" and that it is "like killing a baby". When asked about abortion in cases of rape, he said, "Well, I think that's really sad, but everything happens for a reason. I don't know how that would be a reason. I guess I haven't been in that position, so I wouldn't be able to judge that." In the same interview, Bieber talked about homosexuality, stating that "It's everyone's own decision to do that. It doesn’t affect me and shouldn't affect anyone else", and ''Rolling Stone'' commented, "It is not clear whether he intended to label homosexuality as a lifestyle choice." However, Bieber has also contributed to the It Gets Better Project, a project started in response to the suicide of Billy Lucas, a teenager who was the target of anti-gay bullying.

Bieber has said he is not interested in obtaining United States citizenship, praising Canada as being "the best country in the world", citing its health care system as an example.

Discography

''My World 2.0'' (2010)

''Under the Mistletoe'' (2011)

''Believe'' (2012)

Tours

2009: Urban Behavior Tour

2010–2011: My World Tour

Filmography

rowspan="4" ''Extreme Makeover: Home Edition'' Himself

Year !! Title !! Role !! Notes
rowspan="2"	2009	''True Jackson, VP''	>rowspan="3"| Guest star
''My Date With...''
	Silent Library (MTV series)>Silent Library''
''School Gyrls (film)	School Gyrls''	Cameo
''Saturday Night Live''
''CSI: Crime Scene Investigation''	Jason McCann
''Hubworld''	Guest star
''The X Factor (UK)''	Performer
rowspan="9"	2011	|	Guest star
''CSI: Crime Scene Investigation''	Jason McCann
''Khloé & Lamar''	|Episode:The Father In Law (uncredited) Himself playing the NBA Celebrity All Star Game
''Saturday Night Live''
''Justin Bieber: Never Say Never''	Himself
''Dancing With The Stars''	Guest star
''So Random!''	Himself
''Disney Parks Christmas Day Parade''	Guest star
''The X Factor (UK)''	Performer

Awards and nominations

References

Further reading

External links

Category:1994 births Category:Canadian child singers Category:Canadian Christians Category:Canadian dance musicians Category:Canadian expatriate musicians in the United States Category:Canadian Internet personalities Category:Canadian male singers Category:Canadian people of French descent Category:Canadian people of German descent Category:Canadian pop singers Category:Canadian rhythm and blues singers Category:Child pop musicians Category:Hip hop singers Category:Island Records artists Category:Musicians from Ontario Category:People from Stratford, Ontario Category:Living people

af:Justin Bieber ar:جستين بيبر an:Justin Bieber az:Castin Biber bn:জাস্টিন বিবার zh-min-nan:Justin Bieber bcl:Justin Bieber bg:Джъстин Бийбър br:Justin Bieber ca:Justin Bieber cs:Justin Bieber cbk-zam:Justin Bieber cy:Justin Bieber da:Justin Bieber de:Justin Bieber et:Justin Bieber es:Justin Bieber eo:Justin Bieber eu:Justin Bieber fa:جاستین بیبر fo:Justin Bieber fr:Justin Bieber fy:Justin Bieber ga:Justin Bieber gd:Justin Bieber gl:Justin Bieber ko:저스틴 비버 hy:Ջասթին Բիբեր hr:Justin Bieber ig:Justin Bieber ilo:Justin Bieber id:Justin Bieber is:Justin Bieber it:Justin Bieber he:ג'סטין ביבר jv:Justin Bieber ka:ჯასტინ ბიბერი kk:Джастин Бибер la:Iustinus Bieber lv:Džastins Bībers lb:Justin Bieber lt:Justin Bieber ln:Justin Bieber hu:Justin Bieber mk:Џастин Бибер mg:Justin Bieber ml:ജസ്റ്റിൻ ബെയ്ബെർ mr:जस्टिन बीबर xmf:ჯასთინ ბიბერი ms:Justin Bieber mn:Жастин Бибер my:ဂျပ်စတင် ဘီဘာ nl:Justin Bieber ne:जस्टिन बीबर ja:ジャスティン・ビーバー no:Justin Bieber nn:Justin Bieber uz:Justin Bieber pcd:Justin Bieber pl:Justin Bieber pt:Justin Bieber ro:Justin Bieber ru:Бибер, Джастин sq:Justin Bieber simple:Justin Bieber sk:Justin Bieber sl:Justin Bieber sr:Џастин Бибер sh:Justin Bieber su:Justin Bieber fi:Justin Bieber sv:Justin Bieber tl:Justin Bieber ta:ஜஸ்டின் பீபர் tt:Джастин Бибер th:จัสติน บีเบอร์ tr:Justin Bieber uk:Джастін Бібер vi:Justin Bieber yi:זשאסטין ביבער yo:Justin Bieber zh:贾斯汀·比伯

name	John Leguizamo
birth name	Jonathan Alberto Leguizamo
birth date	July 22, 1964
birth place	Bogotá, Colombia
other name	Johnny Legs, Jonathan Alberto Leguizamo, Jonathon Alberto Leguizamo, Jonathan Leguizamo, Jonathon Leguizamo, John Alberto Leguizamo, Jon Leguizamo, Jon Alberto Leguizamo, John Albert Leguizamo
medium	Stand-up, film, television
nationality	Colombian
active	1984–present
spouse	Yelba Osorio (1994–96; divorced)Justine Maurer (2003–present; 2 children)
domesticpartner	Carolyn McDermott (1986–91)
notable work	FreakSuper Mario Bros.Carlito's WaySpawnMoulin Rouge!ERIce AgeLand of the Dead }}

Jonathan Alberto "John" Leguizamo (born July 22, 1964) is a Colombian-born American actor, producer, voice artist, and comedian.

Early life

John Leguizamo was born in Bogotá, Colombia, to Alberto and Luz Leguizamo, both Colombian nationals. According to Leguizamo, his paternal grandfather was of Italian descent and his maternal grandfather was Lebanese. Leguizamo has also described himself as being of Amerindian and Mestizo heritage. Leguizamo's father was once an aspiring film director and studied at Cinecittà, but eventually dropped out due to lack of finances. When Leguizamo was four years old, his family emigrated to the United States and lived in various neighborhoods of Queens in New York City, including Jackson Heights. Leguizamo attended the Joseph Pulitzer Middle School (I.S.145) and later the Murry Bergtraum High School. As a student at Murry Bergtraum, Leguizamo wrote comedy material and tested it out on his classmates. He was voted "Most Talkative" by his fellow classmates. After graduating from high school, he began his theater career as an undergraduate at NYU's Tisch School of the Arts in which he eventually dropped out to seek a stand-up comedy career. Post NYU Leguizamo enrolled at Long Island University C.W. Post Campus where he took theater classes.

Career

Early career

Leguizamo started out as a stand-up comic doing the New York nightclub circuit. In 1984, he made his television debut with a small part in ''Miami Vice''. His other early roles include: an extra in Madonna's ''Borderline'' video (1984) playing a friend of Madonna's boyfriend; ''Mixed Blood'' (1985); ''Casualties of War'' (1989); ''Die Hard 2'' (1990); ''Hangin' with the Homeboys'' (1991); the robber in ''Regarding Henry'' (1991) and ''Night Owl'' (a.k.a. ''Nite Owl'') (1993), which was filmed from 1989–1991.

Film

In 1992, he starred in "Whispers in the Dark" as John Castillo. In 1993 Leguizamo was offered the lead part as Luigi in the superhero film ''Super Mario Bros.'', based on the Mario video game franchise. Although it started his acting career in Hollywood and became one of his memorable roles, it was universally considered a critical and financial failure. However, it provided a boost to his career, allowing him to appear in better comedic roles in the following years, which helped the film reached its cult film status among his fans. That same year, he had a prominent role in Brian De Palma's ''Carlito's Way'' as Carlito Brigante's (Al Pacino) nemesis, "Benny Blanco from the Bronx," which also boosted his career in serious roles.

Leguizamo also starred in ''Romeo + Juliet'' as Tybalt Capulet, as Violator in ''Spawn'', Cholo in ''Land of the Dead'' and Pestario 'Pest' Vargas in ''The Pest''. In 1995, he starred as drag queen Chi-Chi Rodriguez in ''To Wong Foo, Thanks for Everything! Julie Newmar'' and in the 1996 action film ''Executive Decision'' as Captain Rat. In 2002, he starred in the movie ''Empire''.

In 2000, Leguizamo played two genies in the Emmy Award winning miniseries ''Arabian Nights''.

To promote the 2001 movie ''Moulin Rouge!'', he appeared on a celebrity edition of ''Who Wants to Be a Millionaire?'' with Kelly Ripa, Kevin Sorbo, Alfre Woodard, Martin Short and Chevy Chase. Appearing as the first celebrity to sit in the hot seat, he eventually tried for $125,000, but got the answer wrong. Later in 2002, on the syndicated version, a question about the movie featured his character and Meredith Vieira mentioned that Leguizamo had played Lautrec and had been on the show.

In 2002 he voiced Sid the Sloth for the film ''Ice Age'', eventually repeating it for the sequels ''Ice Age: The Meltdown'' and ''Ice Age: Dawn of the Dinosaurs''. The game versions of the films used his voice were used for PlayStation 2, GameCube, Xbox, PC, and Mac. In 2003, he voice-acted Globox from ''Rayman 3: Hoodlum Havoc''. Leguizamo portrayed Paul in the Brad Anderson thriller film ''Vanishing on 7th Street''.

Television

In 1995 Leguizamo created, produced, wrote, and starred in the 1995 Latino-oriented variety show called ''House of Buggin''' on Fox Television. Some audiences saw this as the Latino version of ''In Living Color''. The show showcased Leguizamo's well-known ability to assume a wide variety of colorful, energetic characters, but due to poor ratings the show ran less than one season.

During the 2005–06 television season, Leguizamo joined the cast of the show ''ER'', playing the emotionally disturbed Dr. Victor Clemente, a new attending who is keen on introducing the staff of County General to better ways of treating patients and cutting-edge technology. Clemente, however, was plagued with personal problems and was fired from the hospital near the end of the season. Dr. Clemente's departure from the show was a blessing for Leguizamo. He revealed to CraveOnline that he was not happy working on the television program. "I was depressed doing ''ER''," he admitted, "I started gaining weight, I was eating donuts, I started smoking again. I’m eating McDonald's, things that I know when I’m depressed I do. I tried to kill myself internally."

In 2005, he guest starred on ''Dora the Explorer'' as Captain Pirate Piggy. In 2006, Leguizamo starred in the television pilot for ''Edison,'' a 2006 CBS drama about an Los Angeles detective (played by Leguizamo) who relied on impersonations and disguises to solve crimes. Other cast members included Currie Graham and Deidrie Henry. Kevin Rodney Sullivan directed from a script by Ron Milbauer and Terri Hughes. Leguizamo and David Hoberman also served as executive producers.

In July 2007, Spike TV aired their drama series ''The Kill Point'', starring Leguizamo, Donnie Wahlberg and Michael Hyatt. The show was an eight-part series revolving around ex-war veterans whose bank robbery went wrong, thus ending in a hostage situation. Despite high ratings, ''The Kill Point'' was not renewed for a second season.

In 2010, Leguizamo also guest starred on ''The Electric Company'' as himself, rhyming about commas and quotation marks.

Broadway and theater

In 1991, he also wrote and took part in the Off-Broadway production ''Mambo Mouth'', where he played seven different characters. ''Mambo Mouth'' won an Obie Award and an Outer Critics Award. He was listed as one of 12 "Promising New Actors of 1991" in "John Willis' Screen Worlds Vol. 43".

In 1993, Leguizamo wrote and participated in ''Spic-O-Rama'', where he made fun of the stereotyping of Latinos in the United States. The production won a Drama Desk Award and four Cable ACE Awards. Both ''Mambo Mouth'' and ''Spic-O-Rama'' were later filmed for presentation on HBO.

In 1998, he debuted on Broadway in the production of ''Freak'', which was basically about his whole life experience with his family, how he had a troubled family, and a messed up life. In 2000, it was turned into an HBO film by director Spike Lee. The show won him the Drama Desk Award for Outstanding One-Person Show.

In 2002, he wrote and performed in ''Sexaholix... A Love Story'' which explained his love life and how he started his own family.

In June 2010, Leguizamo wrote and participated in ''Klass Klown'', a semi-autobiographical one-man show based on his memoir ''Pimps, Hos, Playa Hatas, and All the Rest of My Hollywood Friends: My Life''.

In November 2010, Leguizamo performed in ''Ghetto Klown'' at the Canadian Stage's Berkeley Street Theatre in Toronto, Canada.

The show opened on Broadway in March 2011 at the Lyceum Theatre, after Leguizamo performed an 'unplugged' version of the show under the title ''John Leguizamo Warms Up'' at Chicago's Royal George Theatre in February. The show, an in-depth look at Leguizamo's professional career as it intercepted with his personal life, opened to critical raves and was extended through July 10th, 2011. A CD, produced through the legendary Fania Records was distributed along with the show's release, adding a musical and more personal element to the show. The show's official webpage can be viewed here Ghetto Klown on Broadway. Leguizamo received the Outer Critics Circle Award for Outstanding Solo Performance and the 2011 Drama Desk Award for Outstanding Solo Performance for his work in the show.

In September 2011 Leguizamo will begin an international tour of "Ghetto Klown" in Los Angeles at the Montalban Theatre.

On Record

''John Leguizamo LIVE'' (2001) on RCA Records. The Live CD features the best of Leguizamo's stage routines at the time. Leguizamo gives his audience a primer on the history and culture of Latinos in America. The story starts with the dubious tale of the mating of an Inca princess with a Spanish conquistador, thus creating the original dysfunctional Latin family with Leguizamo providing all the voices

The CD includes a musical intermission, with two salsa/hip-hop tunes, "The Night Before Christmas" and "Gotta Get Some".

The Mac-and-PC compatible enhanced CD includes footage from John on tour at various US locations and two interactive games; "Spanish Fly Pick-Up Line", which lets the person at the keyboard click to choose an appropriate response to a number cheesy pickup lines, delivered by an animated version of Leguizamo, and "Six Degrees of Leguizamo", a drag-and-drop brain-teaser modeled on the "Six Degrees of Kevin Bacon" phenomena. The number of correct answer sequences to this game attest to the Leguizamo's prolific career.

Personal life

Leguizamo married Justine Maurer on June 28, 2003 in a Catholic-Jewish ceremony. They have two children, daughter Allegra Sky (born October 23, 1999) and son Ryder Lee (born December 5, 2000), and live in New York City.

In an interview with Playboy Magazine, Leguizamo notably described how, despite wife Justine being Jewish, he was determined not to adhere to the Jewish tradition of circumcision for boys when they had children. He said: "We talked about it, and I said there's no way they're going to be circumcised, and she was totally cool with it. It's a beautiful thing."

In 2008, he received the Rita Moreno HOLA Award for Excellence from the Hispanic Organization of Latin Actors (HOLA).

He was a recipient of the 2011 Made in NY Award from the City of New York. Other recipients included actor Matt Damon, location-based social network foursquare and director Sidney Lumet.

Memoirs

In October 2006, Leguizamo's memoir, ''Pimps, Hos, Playa Hatas and All the Rest of My Hollywood Friends: My Life'', was released. During an interview on ''Late Night with Conan O'Brien'', Leguizamo stated that his memoir was very frank about odd experiences involving other celebrities and co-stars he had worked with. He stated that working with Arnold Schwarzenegger on ''Collateral Damage'' was one of the most enjoyable experiences he had as an actor. He also said that Arnold's accent let him say things that others would think were sexist or homophobic if said by someone else, that Steven Seagal was an egotist with diva tendencies, Kurt Russell continuously called him a "faggot", and that Leonardo DiCaprio was a "patron of prostitutes."

As of 2009, Leguizamo has produced over 10 films (including the film ''Piñero''), starred or co-starred in over 75 films, starred on Broadway in several productions winning several awards, made over a dozen TV guest appearances and has helped produce or star in many other similar television shows.

Nationality

On June 10, 2011, Alberto Leguizamo, John's father, declared in an interview published in a New York Hispanic newspaper "El Diaro Newspaper", that he (the father) was not Puerto Rican, that he is Colombian and therefore his son (John) was not half Puerto Rican as he has always stated. John Leguizamo had always declared that he was Puerto Rican on his father's side which was one of the reasons that he was selected as the Puerto Rican Day Parade Global Ambassador of the Arts. In response to his father's allegations, Leguizamo stated that his grandfather was of Puerto Rican descent. A spokesman for the National Puerto Rican Day Parade has stated that Leguizamo would not be stripped of his ambassadorship. Leguizamo marched in the parade on June 12, 2011.

Filmography

Year	Film	Role	Notes
1985		Macetero	Film Debut
1989		PFC. Antonio Diaz
	''Street Hunter''	Angel
''Gentille alouette''	Ortiz
	Ignacio
''Die Hard 2''	Burke
		Chanchi
''Hangin' with the Homeboys''	Johnny
''Out for Justice''	Boy in Alley
''Regarding Henry''	Liquor Store Gunman
''N.Y.P.D. Mounted''	Unknown Role	TV Movie
	''Puerto Rican Mambo (Not A Musicial)''	Guess my nationality guy
	John Castillo
''Time Expired''	Ruby
		Angel
	Luigi
''Carlito's Way''	Benny Blanco
	''A Pyromaniac's Love Story''	Sergio
''To Wong Foo, Thanks for Everything! Julie Newmar''	Chi-Chi	Nomination: Golden Globe for Best Supporting Actor – Motion Picture
	''Executive Decision''	Rat
	Manny
''Romeo + Juliet''	Tybalt Capulet
		Pestario "Pest" Vargas
''A Brother's Kiss''	Lefty
	Violator
	''Frogs for Snakes''	Zip
	Chino
	Rat	Voice
	''Joe the King''	Jorge
''Summer of Sam''	Vinny
		Genie	TV Movie
''Titan A.E.''	Gune	Voice
	Seymour
	''Moulin Rouge!''	Toulouse-Lautrec
''What's the Worst That Could Happen?''	Berger
		Victor Rosa
	Felix Ramirez
	Dean Singer
		Voice
	Keith Lang	TV Movie
''Spun''	Spider Mike
2003	''Undefeated''	Lex Vargas
2004	''Crónicas''	Manolo Bonilla
		Beck
	Dodge
''Land of the Dead''	Cholo DeMora
''Sueño''	Antonio
		Sean Edison	TV Movie
''The Alibi''	Hannibal
''Ice Age: The Meltdown''		Voice
''The Groomsmen''	T.C.
	''Where God Left His Shoes''	Frank Diaz
''The Babysitters''	Michael Beltran
	Felix De La Pena
	Lorenzo Daza
	''Paraiso Travel''	Roger Pena
	Julian
''Miracle at St. Anna''	Enrico
''Righteous Kill''	Det. Simon Perez
''Nothing Like the Holidays''	Mauricio Rodriguez
''Surviving Sid''	Sid	Direct-to-Video
		Dante/Perfecto Mendoza
	Jed
''Ice Age: Dawn of the Dinosaurs''		Voice
	Freek
	''Repo Men''	Asbury	Uncredited
''Vanishing on 7th Street''	Paul
	Unknown Role	Direct-to-Video / Short Film
		Jimmy Alpha
''Fugly!''	Jesse
	Val Valenzuela
		TBA	(''In production'')
''Ice Age: Continental Drift''		Voice
Television
! Year	! Title	! Role	! Notes
1986–1989	''Miami Vice''	Ivan Calderone	3 episodes
2000–2003	''The Brothers Garcia''	Narrator	5 episodes
2002	''Sesame Street''	Himself	1 episode
2004	''Dora the Explorer''	Silly Mail Bird	1 episode
2005–2006		Dr. Victor Clemente
2006	''My Name Is Earl''	Uncle Diego	2 episodes
2007	''The Kill Point''	Mr. Wolf	8 episodes
Broadway
! Year	! Title	! Role	! Notes
1991	''Mambo Mouth''	Various
1993	''Spic-O-Rama''	Various
1998		Himself	Won: Drama Desk Award for Outstanding One-Person Show
2002	''Sexaholix... A Love Story''	Himself
2008		Walter Cole
2011	''Ghetto Klown''	Himself
Video games
! Year	! Title	! Role	! Notes
2003	''Rayman 3: Hoodlum Havoc''	Globox	Voice
2006			Voice
2009			Voice

See also

Colombian American

List of famous Colombians

List of hispanophones

References

External links

Official site for John Leguizamo's Ghetto Klown

Facebook page for Ghetto Klown

Q&A; Sessions: John Leguizamo on The Happening at nocheLatina.com

Vanishing on 7th Street Facebook Page

Category:1964 births Category:Actors from New York City Category:American film actors Category:American stage actors Category:American television actors Category:American voice actors Category:American people of Colombian descent Category:American people of Lebanese descent Category:American people of Italian descent Category:Hispanic and Latino American people Category:Colombian people of Lebanese descent Category:Emmy Award winners Category:Hispanic and Latino American actors Category:Living people Category:RCA Records artists Category:Obie Award recipients Category:People from Bogotá Category:People from Jackson Heights, Queens Category:Shakespearean actors

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