Psych 205 chapter 14 PDF

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Dr. Barbara Strock (TA: Sara Valencia Botto); Section 1; Fall Semester 2018...

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Chapter 14: Physical Development in Adolescence Concepts of Adolescence The Biological Perspective - Jean-Jacques Rousseau ฀   believed that the biological upheaval of puberty triggered heightened emotionality, conflict, and defiance of adults - G. Stanley Hall o Ideas based off of Darwin’s theory of evolution o Described adolescence as a cascade of instinctual passions o Extremely turbulent period - Anne Freud o Sigmund Freud’s daughter o As adolescents find intimate partners, inner forces gradually achieve a new, more mature harmony o Young people are working to fulfill their biological destiny (eventually marrying and birthing and raising kids The Social Perspective - current research claims storm and stress notion is greatly exaggerated - overall rate of serious psychological disturbance rises only slightly between childhood and adolescence - Margaret Meade o Anthropologist o First researcher to point out the wide variability in adolescent adjustment o Research in Samoa ▪ Saw that the culture’s relaxed social relationships and openness toward sexuality caused adolescence to the be pleasantest time o Thought the social environment was entirely responsible for the range of teenage experience o In later years, researchers found that Samoan adolescence was not as enjoyable as Meade had concluded A Balanced POV - we know that biological, psychological, and social forces influence adolescent development - biological changes are universal - adolescents’ prior and current experiences affect their success in surmounting these challenges o but do vary between cultures o tribal and village societies ฀   have shorter period of adolescence o industrialized societies ฀   have longer period of adolescence ▪ early adolescence (11-12 to 14): period of rapid pubertal growth ▪ middle adolescence (14 to 16): pubertal changes are now nearly complete ▪ late adolescence (16 to 18): the young person achieves full adult appearance and anticipates assumptions of adult roles

The Physical Transition to Adulthood Hormonal Changes - pituitary gland releases growth hormone and stimulates other glands to produce hormones that act on body tissues, causing them to mature - secretions of GH and thyroxine increase, leadings to tremendous increase in body size and skeletal maturity - hypothalamus ฀   initiates and regulates the hormonal changes of puberty, located at the base of the brain - sexual maturation o sex hormones ฀   cause sexual maturation, begin to rise around 6-8 years old o adrenarche ฀   the adrenal glands on top of each kidney start to release increasing levels of adrenal androgens; starts the physical changes occurring during puberty o everyone has both estrogen (female) and androgens (male) o adrenal androgens ▪ by age 10, levels of adrenal androgens have increase by 10x ▪ for girls ฀   influence girls’ height spurt & stimulates growth of underarm and pubic hair ▪ for boys ฀   little visible effect on boys bc their physical characteristics are mainly influenced by androgen secretions from the testes o estrogen ▪ released by girls’ maturing ovaries ▪ cause the breasts, uterus, and vagina to mature, the body to develop feminine proportions, and fat to accumulate ▪ plays a crucial role in menstrual cycle o testosterone ▪ large amounts released by maturing testes ▪ leads to muscle growth, body and facial hair, and other male sex characteristics ▪ testes secrete a small amount of estrogen also - two main types of pubertal changes o overall body growth o maturation of sexual characteristics - puberty = time of greatest sexual differentiation since prenatal life Body Growth - growth spurt ฀ first outward sign of puberty is the rapid gain in height and weight - body growth for girls ฀   complete for most by age 16 - body growth for boys ฀   complete for most by age 17.5 - body proportions o cephalocaudal trend of infancy and childhood reverses ▪ hands, legs, & feet accelerate first followed by torso o large sex differences in body proportion appear ▪ boys ฀   broader shoulders, longer legs ▪ girls ฀   wider hips, shorter legs

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muscle-fat makeup and other internal changes o girls ▪ around age 8, start to add more fat than boys on their arms, legs, and trunk ▪ increase in muscle (not as much as boys) o boys ▪ arm and leg fat decrease during adolescence ▪ huge increase in muscle (150x more than girls) Motor Development and Physical Activity - gross-motor performance ฀   steadily improves during puberty - girls o slow and gradual gains in motor development o levels off by age 14 - boys o dramatic spurt in strength, speed, and endurance (continues throughout teenage years) o athletic competition is strongly related to peer admiration and self-esteem ▪ bc of this, there’s been an increase in use of performance enhancing drugs in high school boys - by mid-adolescence, big sex differences in sports - daily activity ฀   free-time physical activity declines with age (more extreme w/ girls than boys) - sports & exercise o improve motor performance o influence cognitive and social development o provides lessons in teamwork, problem solving, assertiveness, and competition Sexual Maturation - primary sexual characteristics ฀   changes in physical features involving the reproductive organs directly (ovaries, uterus, vagina, penis, scrotum, testes) - secondary sexual characteristics ฀   changes in physical features related to sexual functioning that are visible on the outside of the body and serve as additional signs of sexual maturity (breast development, underarm and pubic hair) - sexual maturation in girls o menarche ฀   first menstruation o sexual maturity in girls happens once their body is large enough for childbearing - sexual maturation in boys o first sign of puberty in boys ฀   enlargement of the testes o major things that occur ▪ growth of penis ▪ growth spurts ▪ grow taller ▪ facial and body hair ▪ deepening voice o spermarche ฀   first ejaculation

Individual Differences in Pubertal Growth - Things that affect pubertal growth o heredity ▪ contributes substantially to the timing of pubertal changes ▪ identical twins are more similar than fraternal twins in timing of puberty o nutrition & exercise ▪ girls ● large increase in body weight and fat can trigger sexual maturation ● fat cells release leptin which tells girl’s brain to start puberty ● a reason why heavier girls tend to experience puberty earlier ● girls who participate in rigorous athletic training experience puberty later ▪ few studies link body fat and puberty in boys o region of the world ▪ poverty stricken regions where malnutrition & infectious disease are common, menarche is greatly delayed o socioeconomic status ▪ in developing countries, higher class girls reach menarche 6-18 months earlier than lower SES girls o ethnic group ▪ breast and pubic hair development along with menarche occur earlier in African-American girls than Caucasian girls o early family experiences ▪ humans are evolved to be sensitive to the emotional quality of their childhood environments ▪ when kid’s safety and security is at risk, it’s adaptive to develop earlier ▪ happens more often with girls than boys ▪ those with warm, stable family ties reach puberty late The Secular Trend - age of menarche has decreased as nutrition and health care has improved over the years o trends of obesity in the US are now leading to an even younger age of menarche - boys also now reach puberty earlier Brain Development - major changes in brain during adolescence - white matter ฀   myelinated nerve fibers o increases during middle childhood and adolescence o particularly in prefrontal cortex, parietal lobes, and corpus callosum - gray matter ฀   neurons and supportive material o declines during middle childhood and adolescence

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prefrontal cortex becomes a more effective “executive” o oversees and manages the integrated functioning of various areas - these advances occur gradually over teenage years - changes to emotional/social network ฀   as humans become more mature, neurons become more responsive to excitatory neurotransmitters o As a result, adolescents react more strongly to stressful events and experience pleasurable stimuli more intensely o These changes outpace development of cognitive-control work Changing States of Arousal - puberty changes the way the brain regulates sleep o adolescents go to bed much later than younger children even though they still need as much sleep - sleep deprivation leads to o poor performance of cognitive tasks during morning hours o more likely to do worse in school o more likely to suffer from anxiety, irritability, and depressed moods o engage in high risk behaviors The Psychological Impact of Pubertal Events Reactions to Pubertal Changes - reactions to menarche vary greatly o depends on prior knowledge and support from fam members (influenced by cultural attitudes) o girls with no advance info have more shocked and disturbing reactions - reactions to spermarche reflect mixed feelings o many boys know about ejaculation prior to this ▪ but most say nobody spoke to them about it before or during puberty ▪ get most info from reading material or websites - overall, boys get much less social support than girls for the changes of puberty - initiation ceremony ฀   the way many tribal and village societies celebrate the onset of puberty o ritualized announcement to the community that marks an important change in privilege and responsibility Pubertal Change, Emotion, and Social Behavior - adolescent moodiness o higher pubertal hormone levels are linked to greater moodiness o negative moods linked to greater number of negative life events o moods of adolescents are less stable - parent-child relationships o in US, puberty is linked to a rise in intensity of parent-child conflict o adaptive origins ▪ nonhuman primates leave their family around the time of puberty ▪ adolescents in industrialized nations cannot leave their family bc they are still economically dependent so this is the modern substitute o focus largely on everyday matters

o parent-daughter conflict tends to be more intense than parent-son conflict Pubertal Timing - early maturation in boys o relaxed o independent o self-confident o physically attractive o popular among peers o hold leadership positions o athletic o more psychological stress, depressed mood, and problem behaviors than on-time and late maturing boys - late maturation in boys o transient emotional difficulties - early maturation in girls o unpopular o withdrawn o lacking in self-confidence o anxious o prone to depression o fewer leadership positions o more involved in deviant behavior - later maturing girls o regarded as physically attractive o lively o sociable o leaders in school - two main factors contributing to these trends o how closely the adolescent’s body matches cultural ideals of physical attractiveness ▪ body image ฀   conception of and attitude toward their physical appearance ● strong predictor of self-esteem o how well young people fit in physically with their age mates ▪ strong desire to fit in which leads adolescents to participate in problem behaviors - long term consequences of pubertal timing o early maturing girls are at risk of lasting difficulties ▪ depression ▪ frequent changing of sexual partners ▪ poorer quality relationships with friends and family ▪ smaller social networks ▪ lower life satisfaction o early maturing boys ▪ showed good adjustment from ages 14-24 Health Issues

Nutritional Needs - among adolescents, consumption of items high in fat, sugar, and calories has gone down in recent years - iron deficiency is common in adolescence - frequency of family meals is associated with greater intake of fruits, veggies, grains, and calcium rich foods - adolescents (especially girls) tend to be more attracted to fad diets Eating Disorders - anorexia nervosa ฀   an eating disorder in which young people starve themselves because of a compulsive fear of getting fat o 1% of US teenage girls are affected o boys account for 10-15% of anorexia cases (half of these are gay or bisexual young people) o potential negative effects of anorexia ▪ heart muscle can shrink ▪ kidneys fail ▪ irreversible brain damage ▪ loss of bone mass can occur - bulimia nervosa ฀   an eating disorder in which young people (primary girls) engage in strict dieting and excessive exercise accompanied by binge eating, often followed by deliberate vomiting and purging with laxatives o more common than anorexia o 2-4% of teenagers - binge-eating disorder ฀   binging at least once a week for 3+ months without compensatory behavior o typically leads to weight gain and obesity Injuries - rate of unintentional injuries increases during adolescence - three major causes of adolescent injury o car accidents are the leading killer of US teenagers o firearms cause the majority of other fatal injuries o sports-related injuries ▪ concussions are a major concern ● can have lasting effects on cognitive and emotional functioning Sexual Activity - hormonal changes in puberty lead to an increase in sex drive - sexual attitudes in north America are fairly restrictive - most people learn about sex from friends, books, magazines, movies, TV, and the internet - adolescent sexual attitudes and behavior o sexual attitudes of US adolescents and adults have become more liberal in recent years ▪ more approval of premarital sex ▪ past 15 years though has become slightly more conservative (largely bc of increase risk of AIDS and other STDs)

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characteristics of adolescents who engage in early sexual activity o 74% if young people in the US have sex before they turn 20 o >10% have sex before 14 o younger sexually experienced teenagers are less likely to be romantically involved with a partner or to use birth control o things linked to early and frequent teenage sexual activity ▪ childhood impulsivity ▪ weak sense of personal control over life events ▪ early pubertal timing ▪ parental divorce ▪ single-parent or stepfamily homes ▪ large family size ▪ little or no religious involvement ▪ weak parental monitoring ▪ disrupted parent-child communication ▪ sexually active friends or older siblings ▪ poor school performance ▪ lower educational aspirations ▪ tendency to engage in norm-violating acts (alcohol or drugs) o early sexual activity is more common among lower socioeconomic status - contraceptive use o 18% of sexually active teenagers in the US don’t use contraception consistently o teenagers who have good relationships w parents and talk to them openly about sex and contraception are more likely to use birth control - sexual orientation o heredity makes an important contribution to sexual orientation ▪ identical twins are more likely to have the same sexual identity than fraternal twins ▪ certain genes affect the level of impact of prenatal sex hormones which can modify brain structures in ways that induce homosexual feelings and behavior o genetic and environmental factors can alter prenatal hormones o girls exposed prenatally to high levels of androgens or estrogens are more likely to develop lesbian or bisexual orientations Sexually Transmitted Infections - people 15-24 have the highest rates of STIs - most serious STI is HIV/AIDS Adolescent Pregnancy and Parenthood - US adolescent pregnancy rate is higher than other industrialized nations - ¼ of US adolescent pregnancies end in abortion - correlates and consequences of adolescent parenthood o adolescents don’t have a clear path for their lives – very difficult to raise a child at this time o teenage parents are much more likely to be poor

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often come from families with low parental warmth and involvement, domestic violence, child abuse and neglect, repeated parental divorce and remarriage o the lives of teenage parents often worsen after the baby is born ▪ less likely to finish high school ▪ less likely to get married ▪ less likely to have secure employment ▪ 35% become pregnant again within 2 years ▪ more likely to get divorced - prevention strategies o need to address the factors underlying early sexual activity and lack of contraceptive use o need better sex education Substance Use and Abuse - alcohol and drug use is pervasive amongst teenagers in industrialized nations - there’s been a decline since the mid-1990s (probably from greater focus on anti-drug campaigns) - drug taking reflects the sensation seeking of teenage years - minimal experimenters ฀   those who try alcohol, tobacco, or marijuana but don’t become addicted o usually psychologically healthy, sociable, curious young people - correlates and consequences of adolescent substance abuse o young drug abusers ▪ impulsive, disruptive, hostile people (even in early childhood this can be seen) ▪ express their unhappiness through antisocial acts o environmental factors also contribute ▪ low SES ▪ family mental health problems ▪ parents and older sibling drug and alcohol abuse ▪ lack of parental warmth and involvement ▪ physical and sexual abuse ▪ poor school performance o introducing drugs to the still developing adolescent brain can be very harmful - prevention and treatment o combination of features used in school and community programs to reduce drug experimentation ▪ promote effective parenting (including monitoring child’s activities) ▪ teach skills for resisting peer pressure ▪ reduce the social acceptability of drug taking by emphasizing health and safety risks...