Presentation on theme: "Physical and Cognitive Development in Adolescence"— Presentation transcript:
1Physical and Cognitive Development in Adolescence Chapter 11:Physical and Cognitive Development in Adolescence
2In This Chapter Physical changes Adolescent sexuality Adolescent healthChanges in thinking and memorySchooling
3Adolescence Period of tremendous physical and cognitive growth Adolescence: transitional time between childhood and adulthoodTremendous physical and cognitive growthTime of risk-taking and opportunityPeriod of tremendous physical and cognitive growthAble to devise new, complex plansA time of risk and opportunitySome risks have long-lasting consequences
4Physical Changes Other Body Systems: Growth Spurts First growth spurtSecond growth spurtCephalocaudal/ proximodistal patternsJoint developmentGender differencesMuscle fibersHeart and lungBody fat levelsGender differencesKurt Fisher and Samuel Rose believe that a qualitatively different neural network emerges during the brain growth spurt that occurs between 13 and 15.First Brain Growth SpurtBetween 13 and 15Cerebral cortex thickensNeuronal pathways more efficientMore energy consumed during growth spurtTakes place in spatial perception and motor areasEnables abstract thought and reflection on cognitive processesSecond Brain Growth SpurtBegins approximately age 17Frontal lobes of brainAssociated with logic and planning
5Physical Changes The Brain Two major growth spurts in teenage years years: Largely related to parts of brain that control spatial perceptions and motor functions 15+ years: Changes in prefrontal cortex responsible for executive processingTwo major growth spurts in teenage years13-15 years: largely related to parts of brain that control spatial perceptions and motor functions; enables teens to think abstractly and metacognitively15+ years: changes in prefrontal cortex; responsible for executive processing; contributes to conscious control, social perception, and organized thought processes
6Physical Changes The Skeletal System Growth patternsGender differencesJoint developmentGrowth may be 3 – 6 inches a yearGirls attain most of their height by 16Boys continue to grow until 18 – 20Hands and feet are the first to growThe trunk is the slowest-growingJoint development improves coordinationThis growth may occur for several years.
7Physical Changes The Muscular System What do you know about…?Growth patternsGender differencesMuscle fibers become thicker and denserBy age 17, boys can be as much as 3 times stronger than girlsMen – 40% of total body mass is muscleWomen – 24% of total mass is muscleLargely a result of hormonal differencesGirls have a rise in body fat while boys have a dropCanadian study of teenagers’ strength measured by hanging from a bar with eyes level to the bar.Girls have a rise in body fat from 21% to 24% by age 17, while boys have a drop from 16.1% to 14%.
8Physical Changes The Heart and Lungs What do you know about…?Growth patternsGender differencesIncrease in sizeHeart rate dropsGreater change in boys than in girlsImproved capacity for sustained physical effortBoys gain a clear advantage in endurance, as well as in size, strength, and speed
9Physical Changes: Milestones of Puberty Puberty: Changes needed for reproductive maturityEndocrine glandsPituitary glandEndocrine glandsSecrete hormones governing pubertal growth and physical changesTestes and ovaries developSex hormones releasedTestosterone for malesEstradiol for girlsPituitary glandMaster gland – triggers hormone release from other glandsGonadotrophic hormones – responsible for development of sex organsSee Table 11.1The thyroid also secretes thyroid stimulating hormone and general growth hormone to affect growth.
10Testosterone for males Estradiol for girls Pituitary gland signals adrenal glandAndrogen producedPituitary hormones stimulate growth of ovaries or testesTestosterone and estradiol producedOther growth hormones producedMilestones of PubertyEndocrine glandsSecrete hormones governing pubertal growth and physical changesTestes and ovaries developSex hormones releasedTestosterone for malesEstradiol for girlsPituitary glandMaster gland – triggers hormone release from other glandsGonadotrophic hormones – responsible for development of sex organsSee Table 11.1The thyroid also secretes thyroid stimulating hormone and general growth hormone to affect growth.
11Physical Changes Endocrine and Reproductive Systems: Overview Thyroid glandAdrenal androgenGender differencesThe Thyroid GlandThyroxinGeneral growth hormone and brain developmentAdrenal AndrogenImportant for girlsTriggers growth spurtAffects development of secondary sex characteristicsLess significant for boysDue to large amounts of testosteroneIncrease in sizeHeart rate dropsGreater change in boys than in girlsImproved capacity for sustained physical effortBoys gain a clear advantage in endurance, as well as in size, strength, and speedThe thyroid interacts with adrenal androgen to promote growth.Hormonal changes trigger changes in the brain, bones, muscles, and other body organs.
12Physical Changes Sexual Development in Girls: Secular Trend Menarche: First menstruationOccurs 2 years after beginning of other visible signsPregnancy can occur after menarcheOccurs 2 years after beginning of other visible signsAverage age – between 12 and 13Irregular menstrual cycles first few years.Ovum may not be produced during every cycleSecular trendLowering of the age of menarche by 4 months per decadeDue mainly to changes in diet and lifestylePregnancy can occur after menarche
13Physical Changes Endocrine and Reproductive Systems: Sex Characteristics Primary sex characteristicsGrowth of testes and penisGrowth of ovaries, uterus, and vaginaSecondary sex characteristicsBreast developmentChanging voice pitchBeard growthBody hairSee Table 11.2
14Physical Changes Sexual Development in Girls: Secular Trend Secular trend: Timing of menarcheLowering of the age of menarche by 4 months per decadeDue mainly to changes in diet and lifestyleSecular trendLowering of the age of menarche by 4 months per decadeDue mainly to changes in diet and lifestyleHormonal changes that triggers appearance of these characteristics also signals body’s weight regulation mechanisms to increase fat storesPregnancy can occur after menarche
15Physical Changes Sexual Development in Boys Sperm production begins between 12 and 14First ejaculation about age 13 or 14Genital development and pubic hair development precedes the end of the growth spurt.Development of beard and voice changes occur near the end of the sequenceBOYS
16Physical Changes Sexual Development in Girls Heredity and behavioral factors influence hormonal secretionsMajor body changes before age 11 or 12; consistently more negative body imageSocial context influences changeGIRLSGirls must have 17% body fat to enter puberty and 22% body fat to maintain regularly monthly cycles once menarche occurs.Problem behaviors in early developing girls include getting into trouble in school and at home, more likely to get involved with misbehaving peer groups, engaging in delinquent behavior, depression, and smoking.Heredity and behavioral factors influence hormonal secretionsBody fat linked to beginning of puberty for girlsEarly developing girlsMajor body changes before age 11 or 12Consistently more negative body imageMore likely to show problem behaviorsEarly or late developing boys associated with depressionEarly developing boys may be associated with leadershipSocial context of changeActivities that inhibit development of body fat may delay puberty, such as sustained strenuous exercise
17Physical Changes Sexual Behavior: Overview Boys more sexually active than girlsReports of sexual intercourse varies across ethnic groupsRate declined substantially over last three decadesSee Figure 11.1Boys more sexually active than girlsSexual activity increases with ageReports of sexual intercourse varies across ethnic groups61% of African Americans43% of Hispanics39% of Caucasians
18Physical Changes Sexual Behavior: Early Sexuality Social Factors PovertyUnsupervised by adultsMore likely to use alcoholMore likely to be abused/neglectedSocial FactorsSocial factorsPovertyUnsupervised by adultsMore likely to use alcoholMore likely to be abused/neglectedSexually active is defined as having had sex at least once within 3 months of responding to the survey.
19Figure 11.1 Sexual Activity in High School Students Graph illustrates data from a representative sample of more than 15,000 high school students interviewed in 2009Figure 11.1
20Physical Changes Prevalence of Sexual Behavior Age of sexual activity initiation1988 (15-19 yrs) (15-19 yrs)60% Males 43% Males51% Females 42% FemalesWhat do these data tell us?
21Physical Changes Sexual Behavior Girls who are sexually activeEarly menarcheLow interest in school and school activitiesEarly datingHistory of sexual abuseA higher number of risk factors increases likelihood of sexual activity
22Physical Changes Sexual Behavior: Moral Beliefs Activities and moral beliefs influence lower sexual activity among teens who:Believe premarital sex is wrongAttend religious servicesParticipate in school activitiesDo not use alcohol
23Physical Changes Sexual Behavior and Education Despite school units, teens show ignorance of STDsFail to discuss condom useAbstinence and contraceptive education still controversial in many schoolsDespite school units, teens show ignorance of STDsFail to discuss condom use57% female and 79% males use condoms30% sexually active females use the pill (15-17 yrs.)Abstinence and contraceptive education still controversial in many schools
24Adolescent Sexuality Adolescent Pregnancy Higher in U.S. than many other industrialized countries.Far more frequent among older adolescents.Relative frequency of teens who are unmarried has increased but teen birth rates have dropped overall.Higher in the U.S. than many other industrialized countries, such as Israel or Japan17% of African American births8% of Caucasian births14% of Hispanic birthsFar more frequent among older adolescentsTeen birth rates have droppedRelative frequency of teens who are unmarried has increased
25Physical Changes Adolescent Pregnancy Ethnic differences in teens who marryAfrican AmericansHispanic AmericansCaucasian AmericansEthnic differences in teens who marryLess than 5% of African American teen mothers marry the baby’s father26% of Hispanic American teen mothers marry the baby’s father41% of Caucasian American teen mothers marry the baby’s fatherOverall, only 17% of teen mothers maintain romantic relationships with their babies’ fathers
26Physical Changes Adolescent Pregnancy Factors in teenage pregnancyOnset age of sexual activityPoverty and family influenceLess school successLess contraception useLess teen pregnancy among girls who do well in schoolMore likely to use contraceptives if sexually activeMore likely to have good communication about sex and contraception with their mothers
27Physical Changes Adolescent Pregnancy MythReality1/3 of teen pregnancies end in abortion14% result in miscarriage7% of Whites and 1% of African American teens carry the baby to term and place it up for adoptionWhat happens when teens get pregnant?
28Physical Changes Adolescent Pregnancy: Children of Teen Mothers Negative OutcomesAchieve developmental milestones more slowly when infantsGrow up in povertyPositive PossibilitiesNegative effects can be mitigated by support from girl’s own parentsStaying in school and social programs positively help both child and mother
29Physical Changes Sexual Minority Youth Gay, Lesbian, and Bisexual AdolescentsRealizationRealization begins in middle schoolFew accept their homosexuality during adolescenceCausePrenatal hormone patterns may be causal factor in homosexualityTwin studies suggest biological basisTwin studies show when one identical twin is homosexual, the probability that the other will be is 50–60%Male homosexuality runs in familiesTwin study findings strengthen a biological basis hypothesis for homosexualityBy adulthood, 94% of people say they are exclusively heterosexual, 5% describe themselves as gay, lesbian, or bisexual
30Physical Changes Transgendered Teens Transgender teen: Psychological gender differs from their biological sexHigher rates of depression and suicideCause is debatedSome undergo sexual reassignment, typically as adults, sometimes as teens Cause/theoriesExposure to atypical androgen amount prenatallyOften report early interests in activities associated with opposite sexDo not exhibit transgenderism after puberty
31Adolescent Health Sensation Seeking Sensation seeking: Desire to experience increased levels of arousal (through risky behavior)Gain peer acceptance and autonomy from parentsResponse to popular media’s messagesBrain growthSensation seeking: desire to experience increased levels of arousal (through risky behavior)Risky behavior may gain peer acceptance and autonomy from parentsPopular media’s messages of sex, violence, drugs, and alcohol may influence risky behaviorTeens not involved in extracurricular activities and who value popularity are at riskOnly 4% of incidents portray potential negative consequences of sexual activity.98% of movies show characters using some substance.
32Adolescent Health Drugs, Alcohol, and Tobacco Use Teen use of drugs down but still a significant problem.Alcohol use is prevalent.Sensation-seeking is related to increased use of alcohol and drugs.Teen use of illicit drugs down less common than in generationsStill significant problemAlcohol use is prevalentSensation-seeking is related to increased use of alcohol and drugs10th graders and 8th graders also report binge drinking (defined as consuming 5 or more drinks on a single occasion).
33Figure 11.2 Illicit Drug Use Trends Among Teenagers See this table to review the percentage of teens who have used illicit drugs in the past 12 months
34True or FalseThe decline in teen use of illicit drugs is due to an increased and better understanding of consequences.Maybe…maybe not. What does the class think? Why?
35Adolescent Health Drugs, Alcohol, and Tobacco Tobacco UseFewer teens are regular smokers than generation ago.Teens who are more likely to smoke are influenced by smoking peers.Tobacco UseFewer teens are regular smokers than a generation agoEducational effortsTeens familiar with health reasons for not smokingAlso want to be attractive romantic partnersTeens who are more likely to smoke areInfluenced by peers who smokeEspecially vulnerable to peers between 15 and 17 years old
36Adolescent Health Body Image and Eating Disorders Eating disorder: Mental disorder in which eating behavior goes beyond everyday experiences with trying to lose weightAnorexia nervosaBulimiaAlthough most teens are weight-conscious, eating disorders are more extreme25% teens have at least one symptoms of eating disorderSufferers have a distorted body imageEating disorders can be fatal; 4-18% starve themselves to death/cardiovascular sysfunctionMore common among girls, and also gay and lesbian teensAnorexia nervosaExtreme dietingIntense fear of gaining weightWeight loss approaching starvationSymptoms may include cessation of menstruation, insensitivity to pain, loss of hair, low blood pressure, and deathMore distorted body image than bulimicBulimiaFrequent cycles of binge eatingPurging through self-induced vomiting, laxatives, or excessive exerciseIntense concern about weightNot abnormally thinFeel intense shame about their behaviorMay experience significant depressionSymptoms include tooth decay, stomach irritation, lowered body temperature, and loss of hair
37What contributes to or causes eating disorders? Stop and Think!What contributes to or causes eating disorders?Negative body imagesGirls who participate in activities such as ballet and gymnasticsEmphasis on thinness as a characteristic of attractive womenGeneral tendency towards mental illnessGirls who internalize the “thin ideal” in middle childhood more dissatisfied with body image.Biological cause-brain dysfunctionHeredityPsychoanalytic-fear of growing upPreexisting psychological health/tendency toward distorted thinking
38Adolescent Health Depression and Suicide IncidenceDepressionSuicideCauses or contributing factorsConsequences5% are depressed at any given timeGirls are twice as likely as boysAssociated with disorder of the pituitary glandCausesGenetic basisGrowing up with a depressed parentLow self-esteemCan hinder academic performanceTherapeutic interventions include medication.SuicideGirls think about suicide more but boys are 5 times as likely to commit suicide.Depression is one ingredient.Aggression is common.Family history of suicide or drug use is often present.Contributing factorsSome triggering stressful eventAn altered mental stateAn opportunity
39??Questions To PonderWho has advantages or disadvantages – early maturing boys or early maturing girls? What happens to late maturing boys or girls? Your friend suffers from anorexia or depression. How do you help her?
40Changes in Thinking And Memory Piaget’s Formal Operational Thought Systematic problem solvingLogicAdolescent egocentrismFormal Operational Stage: Reasoning logically about abstract conceptsKey elementsSystematic problem solvingThe ability to search methodically for an answerLogicHypothetico-deductive reasoningAdolescent egocentrism
41Figure 11.3 Within-Stage Development in Formal Operations These are the results from two of the ten different formal operational tasks used in Martorano’s cross-sectional studyFigure 11.2
42Changes in Thinking And Memory Direct Tests of Piaget’s Views on Formal Operations TasksComplex reasoning tasksMetaphorsDecision-makingEducation levels influence use of formal operational thoughtSee Figure 11.2Older children generally do better on complex reasoning tasks.Formal Operational reasoning enables teens to understand metaphors.Influenced how teens make decisions.Nearly 3/5 of 12th graders did not show future orientation thinking.Formal operational thinking is not used on every problem.Education levels influence the use of formal operational thought.Future orientation thinking in response to a dilemma is associated with formal operational reasoning.
43Changes in Thinking And Memory Advances in Information-Processing Task improvement with ageMetacognitionMetamemoryStrategy use increaseText learningMetacognition, metamemory, and strategy use increase with ageText learningThe ability to summarize a text improves gradually during the second half of adolescenceOutlining improves with age, as wellCapacity to apply memory strategies selectively based on characteristics of memory task, appears early in teen years and continues to improve throughout adolescence
44Why do you think such declines Stop and Think!Research findings show achievement declines after entering high school.Why do you think such declinesmay occur?
45Schooling Transition to Secondary School Is the goal the goal?Middle schoolTask goals: Based on personal standards and desire to become more competentAbility goals: Define success in competitive termsMiddle schoolTask goals – based on personal standards and a desire to become more competentAssociated with greater sense of personal control and positive attitudes about schoolAbility goals – define success in competitive termsStudents may adopt relative standards – good means beating someone else.Most 5th graders have task goals, but by 6th grade most have switched to ability goals.
46Schooling Middle School: Ability Grouping Emphasis on ability groupingStudents may change beliefs about individual abilitiesHigh achieversLow achievers
47Schooling Middle School: School Climate Perception of school climateSuccessful intervention strategiesMentorHomeroom teacherStudent teamsParental involvementPerception of school climateMany students find schools to be impersonal and unsupportive.Providing a student with an adult mentor helps.Homeroom teacherSuccessful interventions improve grades.Organizing teachers and students into teamsTeachers at each grade level devise strategies for student and parental involvement.
48Schooling High School Success Early days of high school set patternActivity participation helps develop psychological attributesTeens who fail one or more classes in the first year of high school are fare less likely than their peers to graduate.Participation in activities in high school helps develop psychological attributes that can’t be acquired elsewhere. Intrinsic motivation was higher in elective classes and extracurricular activities.
49Schooling Gender, Ethnicity, and Science and Math Achievement Girls at risk for achievement losses in transition to high schoolGender gap widest among most intellectually talented studentsGirls suffer in sciences not offering hands-on activitiesGirls often discouraged from taking courses in science
50Schooling Gender, Ethnicity, and Science and Math Achievement Gender gap widens in mathEthnic variations existWhy?Gender gap widens in math, as well.Academically talented girls are often less confident than male counterparts.Ethnic variationsOnly 1/3 of African American and Hispanic students have 2 years of algebra.May not be prepared in 9th grade for higher math classesMay not have been encouraged to go to college and lacked the necessary preparation
51Schooling Dropping Out of High School Links Ethnicity, peer group, low value on completion, history of academic failure Profiles Quiet, disengaged, low-achieving, and poorly adjusted students at high risk Consequences Unemployment, lower wages, depression, and increased criminal activitySocial class is better predictor of school completion than ethnicityWhen a teen’s peer group puts a low value on completion, teens are more likely to drop out.Students with a history of academic failure are at riskLow-income families have higher rates of children who drop out – especially families with single parents.