Adolescent Psychology Ch 2
stage 3
11.5-13 years coarsening of pubic hair (girls and boys) penis size/length (boys) breast enlarges, mound forms (girls)
stage 4
13-15 years coarse hair across pubis, sparing thigh (girls and boys) penis width/glans (boys) breast enlarges, raised areola, mound on mound (girl)
stage 2
8-11.5 years pubic hair appears (pubarche) (boys and girls) testicular enlargement (boys) breast bud forms (thelarche) (girls)
muscle growth
boys experience greater increases in ______ ______ than girls at the end of puberty boys have a muscle to fat ratio of about 3:1 their shoulders widen more
j.m. tanner
british biologist who studied the pattern and sequence of various aspects of physical development during puberty (1960s and 70s) Studied 40-50 years ago on British adolescents who were in foster homes. Used direct physical evaluations and photographs, he made careful assessments of growth and development during puberty. "Tanner stages"- breast development in girls, genital development in males -Stage 1- prepubertal stage, when no physical changes have appeared. -Stage 5- the stage when maturity has been reached and growth is completed. The adolescents he studied were mainly from low SES families, and many of them probably did not receive optimal physical care during childhood. They were not chosen randomly and did not truly represent the larger population of adolescents. His research was longitudinal, which is a study in which the same individuals are followed across time, and data on them are collected on more than one occasion. The range of time can vary from a few weeks to an entire lifetime girls typically began to develop pubic hair at about the same time they developed breast buds, usually 2 years before menarche
puberty
central to adolescent development
early and late pubertal timing in traditional cultures
eligibility for traditional rites of passage based on pubertal maturation for girls adults of community decide when boys are ready for rituals
physical functioning
emerging adulthood is the period of peak ______ _______.
boys response to semenarche
enjoying the pleasurable sensations of it feeling more grown-up but also feeling guilt, surprise, fear rare to receive info from parents prior to experience american boys less likely to discuss or report
tumescent
erect penis
testes growth during puberty
even more pronounced than penis growth during puberty. they increase 2 1/2 times in length and 8 1/2 times in weight, on average. the growth of the testes reflects the production of the million of sperm
the lungs during puberty
experience a similar change to the heart. vital capacity is the measure of lung size, which means the amount of air that can be exhaled after a deep breath, increases rapidly for both boys and girls during puberty but increases more in boys than girls
reaction time
faster in the early 20s than at any other time of life
girls response to menarche in modern-day america
feel more grown up increase in social maturity prestige with peers
400,000; 80,000; one egg; 28; 400
females are born with about ________ immature eggs in each ovary. by puberty, this number has declined to about _______ in each ovary. once a girl reaches menarche and begins having menstrual cycle, _____ _____ develops into a mature egg or ovum, every _____ days or so. females release about ____ ova over the course of their reproductive lives
semenarche
first ejaculation
body fat
girls experience great increases in _____ _____ the muscle to fat ratio for girls is 5:4 their hips widen more
girls response to menarche in other cultures
girls provided little to no information experience characterized by fear and dismay some cultures have negative beliefs about menstruating
cardiac output
peaks at age 25
active genotype-environment correlations
people actively seek out environments that correspond to their genotypic characteristics minimal during early childhood increases during adolescence
evocative genotype-environment correlations
person's inherited characteristics evoke responses from others in their environment (which in turn, affects the environment) effects remain stable from childhood through adulthood
stage 1
prepubertal stage, when no physical changes have appeared no sexual hair (boys and girls) flat-appearing chest with raised nipple (girls)
sexual reproduction; physical functioning; enhancing strength and endurance; physical abilities
puberty changes the body to prepare for ________ ________. it also changes ________ _________, ___________ _______ ______ _________; when these changes are complete during emerging adulthood, we reach the peak of our ______ _______
chinese girls
pubic hair began to develop in most girls in about 2 years after the development of breast buds, and only a few months before menarche
distancing
relationship between parents and adolescents during puberty american majority culture relations become cooler physical closeness less likely (but more talking than childhood) conflict increases adolescents of both sexes are closer to their mothers than fathers not seen in traditional cultures girls often grow closer to mothers
theory of genotype--> environment effects
says both genetics and environment make essential contributions to human development, but... contributions of genes/environments difficult to disentangle because genes influence the environments humans develop in
early and late pubertal timing in developed countries
school system is age ranged comparisons constantly made
premenstrual syndrome
PMS behavioral, emotional, and physical symptoms that occur in the week before menstruation
diets; levels of health and nutrition
Cultural _______ and _____ ____ ______ ___ ______ influence the timing of the initiation of puberty. Cultures define the meaning and significance of pubertal changes in different ways
physical functioning during emerging adulthood
Emerging adulthood is the period of peak physical functioning. Even after maximum height is attained, the bones continue to grow in density, and peak bone mass is reached in the 20s. A measure of physical stamina called maximum oxygen uptake or VO2 max, which reflects the ability of the body to take in oxygen and transport it to various organs, also peaks in the early 20s. Cardiac output, the quantity of blood flow from the heart, peaks at age 25. Reaction time is also faster in the early 20s than at any other time of life. Grip strength among men show the same pattern, with a peak in the 20s followed by a steady decline. One way to demonstrate this at the extreme, in terms of peak performances in athletic activity. Several studies have been conducted on the ages of athletes' best performances. The peak ages have been found to vary depending on the sport, with swimmers youngest (the late teens) and golfers oldest (about age 31). However, for most sports, the peak age of performance comes during the 20s. Emerging adulthood is also the period of the life span with the least susceptibility to physical illnesses. No longer vulnerable to the illnesses and diseases of childhood, and with rare exceptions they are not yet vulnerable to diseases such as cancer and heart disease that rise in prevalence later in adulthood. The immune system is at its most effective during the emerging adult years. The late teens and early 20s are the years of fewest hospital stays and fewest days spent sick in bed at home. Is an exceptionally healthy time of life
obesity
Exceeding a specific body mass index (BMI), which is a ratio of height to weight. The BMI thresholds for obesity are determined by medical authorities and vary depending on age group. About 20% of American adolescents ages 12 to 19 are classified as obese, which is a drastic change from 5% during the period of 1966 to 1980. This problem is especially severe among African Americans and Latinos. Obese adolescents have higher leptin levels, so it may be that increased obesity has contributed to the earlier onset of puberty among African American and Latina girls in recent decades Nearly ⅓ of American adolescents eat at least one fast-food meal per day, and fast food tends to be extremely high in calories, loaded with fat and sugar. The portions have increased dramatically in recent years, as the burgers and drinks and French fry portions have become "supersized." Americans drive in cars more, than walk or ride a bike. Exercise less, especially African American females. Steep decline in physical activity from middle childhood to adolescence. Television watching has been found to be related to obesity, but it cannot explain the cross-national difference in obesity because American adolescents and adolescents in other industrialized countries watch about the same amount of television; so are computer games; heredity cannot be blamed as well, even though adolescents who have obese parents run a higher risk for obesity. One trend that does shed light on the recent increase in obesity in the US is the increased presence of soft drink and junk food machines in schools. ¼ in elementary school, ⅔ in middle school, and 90% in high school there are vending machines. Obesity in adolescence is a source of concern not just because it is unhealthy during the teen years but because it predicts long-term health problems. About 80% of obese adolescents remain obese in adulthood. A variety of health risks result from obesity in adulthood, including diabetes, stroke, and heart disease
the feedback loop in the endocrine system
From infancy onward, a feedback loop runs between the hypothalamus, the pituitary gland, the gonads, and the adrenal glands. It monitors and adjusts the levels of sex hormones. The hypothalamus monitors the levels of androgens and estrogens in the bloodstream, and when the sex hormones reach an optimal level, called the set point (a commonly used metaphor for the set point is a thermostat), the hypothalamus reduces its production of GnRH. The pituitary responds to the reduction in GnRH by reducing its production of FSH, LH, and ACTH The gonads and adrenal glands, in turn, respond to lower levels of FSH and LH by reducing the amount of sex hormones they produce
adolescent growth spurt
One of the earliest signs of puberty for both girls and boys is the _________ _______ _______. At peak height velocity, when the ________ _______ ________ is at its maximum, girls grow at about 3.5 inches per year and boys grow at about 4.1 inches per year girls typically reach the beginning of their growth spurt about 2 years earlier than boys; girls mature about 2 years ahead of boys marks the beginning of the end of growth in height
average age of menarche
The average age of menarche is lowest in developed countries, where adequacy of nutrition and medical care is highest. For girls in the US, the average age of menarche is 12.5. The average is higher in developing countries, where nutrition may be limited and medical care is often rare or nonexistent. African girls in Africa (average age of menarche is as high as 15, 16, or even 17 years old) vs African American girls in the US (average age is 12.2)- their considerably better nutrition and medical care Adolescent girls from affluent families tend to menstruate earlier than girls from poorer families. Economic differences result in differences in the nutrition and medical care these girls receive, which in turn influence the timing of menarche. In most developed countries, the median age of menarche has been more or less stable since about 1970. Human females appear to have a genetically established reaction range for the age of menarche. This means that genes establish a range of possible times when menarche may begin, and environment determines the actual timing of menarche within that range. The reaction range has boundaries: even under relatively unhealthy conditions, most girls will eventually reach menarche, and even in conditions of optimal health there is a lower boundary age that menarche is unlikely to fall below. ****The healthier the environment, the lower the timing of menarche. Girls who are involved in activities in which there is a great deal of pressure to keep down their weight, such as ballet or gymnastics, experience later menarche and have inconsistent periods once they begin to menstruate. The body responds to their low weight as malnutrition and delays menarche. Concern has grown that the timing of other pubertal changes is continuing to fall. Breast development among girls now begins by age 7 for 10% of whites, 15% of latinas, and 23% for african americans. The main cause of this seems to be rising rates in obesity. (puberty is initiated by an increase in body fat) endocrine disruptors- materials in plastics and endrogens added to milk, as possible triggers of early puberty
lifestyles of emerging adults
The lifestyles of many emerging adults often include a variety of factors that undermine health, such as poor nutrition, lack of sleep, and the high stress of trying to juggle school and work or multiple jobs. In the US and other developed countries, the late teens and early 20s are the years of highest incidence of a variety of types of diseases, injury and death due to behavior. Automobile accidents are the leading cause of death among emerging adults in developed countries, and injuries and deaths from automobile accidents are higher in the early 20s than at any other period of the life span; homicide; rates of contracting sexually transmitted infections, included HIV, are the highest in the early 20s; substance use and abuse also peak in early 20s
strength and athletic ability
The sex differences in physical growth and functioning result in sex differences in _____ ____ _____ ______ during adolescence and beyond. Before puberty boys and girls are about equal in strength and athletic performance, but during puberty boys overtake girls, and the difference remains throughout adulthood
kikuyu
a culture in kenya, boys show the first physical changes of puberty before their female peers, which is a reversal of the western pattern
secular trend
a kind of change in a population over time. Historical records are showing a steady decrease in the average age of menarche in Western countries over the past 150 years. The _______ ______ is due to improvements in nutrition and medical care that have taken place during the past 150 years
culturally constructed period of life
adolescence is a... but the biological changes of puberty are a central part of the development, in all cultures biological changes of puberty are similar across cultures, but biological events interact with cultural influences
endocrine system; hormones; development; functioning
all of the changes due to puberty begin with events that occur in the ________ ________ consists of glands in various parts of the body. these glands release chemicals called _________ into the bloodstream, and they affect the _________ and _______ of the body
maximum oxygen uptake
also referred to as VO2 max, peaks in the early 20s
grip strength
among men show the same pattern, with a peak in the 20s followed by a steady decline
7; 9 or 10; 13; short as a year and a half or as long as 6 years
among young people in developed countries, the first pubertal events may occur as early as age ___ in girls and age ___ __ ____ in boys, or as late as age ____. the duration between the initiation of the first pubertal event and full pubertal maturation can be as ___ ___ __ ____ __ ___ ___ __ __ __ __ __ __
adrenal glands
androgens are produced not only by the sex glands but also by the adrenal glands. The pituitary gland increases production of a hormone known as ACTH (adrenocorticotropic hormone), which causes the adrenal glands to increase androgen production. The androgens released by the adrenal gland have the same effects as the androgens released by the testes, such as development of increased body hair
secondary sex characteristics
are other bodily changes of puberty, not including the ones related directly to reproduction
passive genotype-environment correlations
difficult to separate genetic and environmental influences because parents provide both genes and contexts strong in early childhood diminishes in adolescence
puberty rituals for boys
do not focus on particular biological events typically require the young man to display courage, strength, and endurance often violent seen as necessary to face life's challenges as a man
order of pubertal events in girls
downy pubic hair is typically the first sign of the beginning of puberty, followed closely by the appearance of breast buds. The next event for girls is usually the growth spurt, along with the growth of sexual and reproductive organs. Menarche, the development of underarm hair, and the secretion of increased skin oil and sweat occur relatively late in puberty for most girls
uterus
during this time, a lining of blood builds up in the uterus in preparation for the possibility of receiving and providing nutrients for the fertilized egg. if the ovum becomes fertilized by a sperm during its journey to the uterus, the fertilized egg begins dividing immediately. when it reaches the uterus, it implants in the wall of the uterus and continues developing. if the ovum is not fertilized, it is evacuated during menstruation along with the blood lining of the uterus. the uterus doubles in length during puberty, growing to a mature length of about 3 inches, about the size of a closed fist
breast development in girls
go through a series of predictable stages of development. the earliest indication of breast development, a slight enlargement of the breasts known as breast buds, is also one of the first outward signs of puberty in most girls. during this stage, there is also an enlargement of the area surrounding the nipple, called the areola. in the later stages of breast development, the breasts continue to enlarge, and the areola first rises with the nipple to form a mound above the breast, then recedes to the level of the breast while the nipple remains projected
the heart during puberty
in both boys and girls, it becomes larger during puberty on average its weight almost doubles and the heart rate falls, but boys hearts grow more than girls and their heart rate falls to a lower level. by age 17, the average girl's heart rate is about five beats per minute faster than the average boy's.
where does puberty begin earlier?
in cultures where good nutrition and medical care are widely available
set point
in your body, when the levels of the sex hormones fall below their ____ _______, their production by the gonads increases. once the levels rise again to the _____ ______, their production decreases. when puberty begins, the _____ _____ for androgens and estrogens rise in the hypothalamus, with the ____ ____ for androgens rising higher in males than in females and the ____ ____ for estrogens rising higher in females than in males
ovary growth during puberty
increase greatly in size and weight. the growth of the ovaries reflects the growth of maturing ova (eggs). the ovaries alternate months, with one releasing an ovum and then the other. the ovum moves along the fallopian tube and travels to the uterus
vagina
increases in length and its color deepens
egg and sperm production
increases in sex hormones at puberty cause eggs to develop in the ovaries of females and sperm to be produced in the testes of males. the development of the gametes is quite different for the two sexes
role of culture during puberty
influences the timing of biological changes differences in responses to physical/ sexual maturity provides information for how to interpret changes
primary sex characteristics
involve the production of eggs and sperm and the development of sex organs
peak bone mass
is reached in the 20s
labia majora
latin for large lips
labia minora
latin for small lips
flaccid
limp penis
boys late effects of puberty
lower grades in school substance use and deviant behavior into early adulthood
no sperm; until they reach puberty; 30 and 500 million
males have ___ _____ in their testes when they are born, and they do not produce any _____ ___ _____ ______. there are between ___ _____ ____ _______ sperm in the typical male ejaculation
african american
many girls were found to begin developing breast buds and pubic hair considerably earlier than white girls. at age 8, nearly 50% of african american girls had begun to develop breasts or pubic hair or both, compared to 15% of white girls. they were similar in their age of menarche
ovum
mature egg
first ovulation
menarche is not the same as the ______ _______. the majority of a girl's menstrual cycles in the first 2 years after menarche do not include ________, and in the third and fourth years only about one third to one half of cycles include _______. it is only after 4 years of menstruation that girls consistently ovulate with each menstrual cycle
puberty rituals for girls
menarche is the pubertal event that is most often marked by ritual. In many cultures, menarche initiates a monthly ritual related to menstruation that lasts throughout a woman's reproductive life. Common for cultures to have strong beliefs concerning the power of menstrual blood. It is believed to present a danger to the growth and life of crops, to the health of livestock, to the success of hunters, and to the health and well-being of other people, particularly the woman's husband. The behavior and movement of menstruating women are often restricted, including food preparation and consumption, social activities, religious practices, bathing, school attendance, and sexual activities. It is often viewed as having positive powers. Seen as promoting fertility and is used in fertility rituals. Use menstrual blood in the treatment of medical conditions, and some use it to make love potions
boys early effects of puberty
mixed feelings more favorable body images more popular with other boys achieve greater success later in life involved in more delinquency, sex, and substance use
pubertal events vs age
more consistency can be seen in the order of pubertal events than in the ages they begin or the amount of time it takes to complete them
girls late effects of puberty
more minor teasing negative body image before puberty more positive body image in later teens
asynchronicity
not all parts of the body grow at the same pace during the adolescent growth spurt. some parts of the body grow faster than others: The extremities- feet, hands and head are the first to hit the growth spurt, followed by the arms and legs. Some parts of the head grow more than others. The forehead becomes higher and wider, the mouth widens, the lips become fuller, and the chin, ears, and nose become more prominent. The torso, chest and shoulders are the last parts of the body to reach the growth spurt and are therefore the last to reach the end of their growth
why so many?
one reason is that the environment of the female body is not hospitable to sperm. the female's immune system registers sperm as foreign bodies and begins to attack them immediately sperm have, in relation to their size, a long way to go to reach the ovum. it helps to have a lot of sperm because this increases the likelihood that some of them may make it to the ovum at the right time for fertilization to take place= pregnancy
nature-nurture debate
over relative importance of biology and the environment in human development
genetics
similar environments, the variation in the order and timing of pubertal events appears to be due to _______. if two people are similar genetically, they tend to be similar in the timing of pubertal events. identical twins are the most similar of all
bodily changes during puberty
take place as part of puberty but are not directly related to reproduction some develop only for males or females, but for the most part the changes that happen to one sex also happen to the other, to some degree. both grow hair in their pubic areas and underneath their arms, grow facial hair, hairiness on arms and legs. boys also begin to grow hair on their chests, and sometimes on their shoulders and backs as well, whereas girls typically do not both males and females experience various changes in their skin. the sweat glands in the skin increase production, making the skin oilier and more prone to acne, and resulting in a stronger body odor. both experience a deepening of the voice as the vocal cords lengthen, with males experiencing a steeper drop in pitch even breast development occurs in both. about one fourth of boys experience enlargement of the breasts midway through puberty. the enlargement usually resides within a year.
food production and medical care
the definition of culture includes a group's technologies, which are...
vulva growth during puberty
the external sex organs in females. grows substantially in puberty, which includes the labia majora, the labia minora, and the clitoris
order of pubertal events in boys
the first outward sign of puberty is usually the growth of the testes, along with our closely followed by the beginning of pubic hair. These events are followed (about a year later) by the initiation of the growth spurt, and the increased growth of the penis, along with the beginning of the deepening of the voice. Spermarche takes place at age 12 and 14 for most boys. In boys as in girls, the growth of underarm hair and the secretion of increased skin oil and sweat take place relatively late in puberty. Facial hair is also one of the later developments of puberty, usually beginning about 2 years after the first outward events of puberty
spermarche
the first production of sperm in boys and it takes place on average at age 12
peak height velocity
the growth spurt maximum girls reach their final height earlier than boys at about age 15 on average and boys at about age 17
hypothalamus
the hormonal changes of puberty begin here. It is a bean-sized structure located in the lower part of the brain, beneath the cortex. Effects physiological and psychological motivation and functioning in areas such as eating, drinking and sexuality. Stimulates and regulates the production of hormones by other glands. To initiate puberty, the hypothalamus begins to increase its production of GnRH (gonadotropin-releasing hormone) at intervals of 2 hours. This begins a year or two before even the earliest bodily changes of puberty. This increase occurs once a threshold level of body fat is reached. Fat cells produce a protein, leptin, which provides the signal to the hypothalamus to release GnRH.
pituitary gland
the increase in GnRH affects the pituitary gland, which is about half an inch long located at the base of the brain. When GnRH reaches the pituitary gland, it causes hormones called gonadotropins to be released. There are two of them and they are called FSH (follicle-stimulating hormone) and LH (luteinizing hormone). FSH and LH stimulate the development of gametes, which are egg cells in the ovaries of the female and sperm in the testes of male. They also influence the production of sex hormones by the ovaries and testes.
pubescere
the latin word for puberty, which means "to grow hairy"
hypothalamus, pituitary gland, thyroid gland, adrenal gland, gonads or sex glands
the major glands involved in pubertal changes
gonads or sex glands
the ovaries and testes are also known as gonads or sex glands. In response to stimulation from the FSH and LH released by the pituitary gland, the gonads increase their production of the sex hormones. There are two classes of sex hormones: the estrogens-the most important estrogen is estradiol and the androgens- the most important androgen is testosterone. Increases in these hormones are responsible for the observable bodily changes such as breast growth in girls and facial hair in boys
penis growth during puberty
the penis doubles in length and diameter. in its mature form, the flaccid (limp) penis averages 3 to 4 inches in length and about 1 inch in diameter. the tumescent (erect) penis average 5 1/2 to 6 inches in length and 1 1/2 inches in diameter
diet and exercise
the two main causes of obesity
passive gene-environment correlations, evocative gene-environment correlations, and active gene-environment correlations
three genotype-environment effects
girls early effects of puberty
usually negative depression negative body image eating disorders cultural values of image: tall and thin draws attention of older boys/ start behaving older
stage 5
usually>15 the stage when maturity has been reached and growth is completed coarse hair across pubis and medial thigh (boys and girls) penis and testis enlarge to adult size (boys) adult breast contour, areola flattens (girls)