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Physical and Cognitive Development in Adolescence

Chapter 11

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Guideposts for Study

What is adolescence, when does it begin and end, and what opportunities and risks does it entail?

What physical changes do adolescents experience, and how do these changes affect them psychologically?

What brain developments occur during adolescence, and how do they affect adolescent behavior?

What are some common health problems in adolescence, and how can they be prevented?

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Guideposts for Study

How do adolescents’ thinking and use of language differ from younger children’s?

On what basis do adolescents make moral judgments?

What factors affect adolescents’ school success and their educational and vocational planning and preparation?

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Adolescence and Puberty

Adolescence The passage from childhood

to adulthood

Puberty Process that leads to sexual

maturity or fertility

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Adolescence as Social Construction

No such concept in preindustrial societies Today, adolescence is a global phenomenon Time for growth and change Stereotypes of risk-taking behaviors

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Box 11.1 Globalization of Adolescence

Adolescence is no longer a Western phenomenon

In many nonwestern countries, adolescent boys and girls live in separate worlds

Puberty heightens preparation for gender roles

Cultural change is complex

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Puberty

Adrenarche– Between ages 6 and 9– Maturing of the adrenal glands– Production or androgens (DHEA)

Gonadarche– Maturing of the sex organs– Girls: ovaries increase estrogen– Boys: testes increase androgens

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Physical Changes of Puberty

Both males and females:– Growth spurt– Pubic hair– Deeper voice– Muscular growth

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Puberty Onset

Girls – Between ages 8 and 10

Boys – Between ages 9 and 11

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Primary Sex Characteristics

Females– Ovaries– Fallopian tubes– Uterus– Vagina

Males– Testes– Penis– Scrotum– Seminal vesicles– Prostate gland

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Secondary Sex Characteristics

Femaleso Breastso Pelvis changes

Maleso Broad Shoulderso Facial Hair

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Adolescent Growth Spurt

A rapid increase in height and weight Typically lasts about 2 years Results in common ‘gawkiness’ Teens become more concerned

about their appearance

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Signs of Sexual Maturity

Spermarche– First ejaculation– Nocturnal emission (wet dream)– Average at age 13

Menarche– First menstruation (first period)– Average at age 12 ½

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Secular Trend

A decrease in average age of pubertal onset

Possible explanations:– Higher standard of living/better

nutrition– Overweight– Relationship with father

Pheromones

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Adolescent Brain

A “work in progress” Immaturity of adolescent brain has led to

questions of legal responsibility Risk taking comes from two brain networks

o Socioemotional network (i.e. peer influence)o Cognitive control network (responses to stimuli)

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Two Major Brain Changes

Growth Spurt– Chiefly in frontal lobes– Reasoning, judgment, and impulse

control Gray Matter Growth

– Continued myelination– Facilitates maturation of cognitive

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Physical Activity

Exercise in adolescence is usually much less than in childhood.

1/3 of U.S. high school students do NOT engage in enough physical activity.

U.S. adolescents exercise less than in previous generations and less than those other countries.

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Sleep Needs

Average sleep declines to less than 8 hours at age 16

Still, many adolescents do not get enough sleep

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Sleep Patterns

Changes in circadian timing and melatonin may account for tendency to stay up late.

School schedules are out of sync with biological rhythms.– Tendency to be sleepy during the day and

‘sleep in’ on weekends to make up for loss

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Nutrition

U.S. adolescents have less healthy diets than other industrialized countries– Fewer fruits and vegetables– More sweets, chocolates, and junk food

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Obesity/Overweight

U.S. teens are more likely to be overweight than their age-mates in industrialized countries—numbers tripled between 1980 and 2004.– Average teen girl needs ~2200 calories/day– Average teen boy needs ~2800 calories/day

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Body Image

How one believes one looks Concern most intense during adolescence Pattern is more intense with females

� Normal increase in girls’ body fat African-American girls are more satisfied

with their bodies than are Caucasian girls

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Anorexia Nervosa

Self-starvation Distorted body image Constantly dieting and believe they are fat May cause irregularity or cessation of

menstruation Often good students and ‘perfectionists’

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Bulimia Nervosa

Bingeing and undoing of caloric intake on regular basis

‘Undo’ calories by:– Self-induced vomiting– Excessive exercise– Laxatives or enemas– Diuretics– Dieting or fasting

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Treatment of Anorexia and Bulimia

Immediate goal is to get patient to eat and gain weight

Patients may be hospitalized if severely malnourished

Behavior therapy – reward eating Cognitive therapy – change body image Institutional settings and family therapy

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Drug Use and Abuse

Substance Use– Harmful use of alcohol or other drugs

Dependence or Addiction– Can be psychological or physiological– Especially dangerous for adolescents

because of changing brain structures

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Trends in Drug Use

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Risk Factors for Drug Abuse

Difficult temperament Poor impulse control and sensation seeking

Biochemical basis and/or family influence Genetic predisposition or inconsistent

parenting Early and persistent behavior patterns Peer rejection, alienation, or rebelliousness Attitudes toward drug use and early initiation

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Common Adolescent Drugs

AlcoholMarijuanaTobacco

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Depression

Prevalence increases during adolescenceOccurs in 9% ages 12-17, only 40% treated

Girls more susceptible than boys Can manifest as:

– Sadness– Irritability– Boredom– Inability to experience pleasure

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Causes of Death in Adolescence

Vehicular Accidents– Leading cause of death among U.S. teens

Firearms– Homicide, suicide and accidental deaths– One-third of all injury deaths

Suicide– Almost one-fourth of U.S. high-school students

have seriously considered suicide

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Piagetian Cognitive Development: Formal Operations

A capacity for abstract thought A more flexible way to manipulate

information Usually develops around age 11 Also has emotional implications

� “I hate exploitation”

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Piagetian Tasks for Formal Operations

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Hypothetical-Deductive Reasoning

Problem-solving skills Developing a hypothesis and an

experiment to test it Imagining relationships systematically Piaget attributed acquiring this new skill to:

– Brain maturation– Expanding environmental opportunities

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Evaluating Piaget’s Theory

Many late adolescents and adults (around1/3) are incapable of abstract thought

Fails to capture the role or context of the situation

The theory does not fully consider the role of metacognition

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Elkind: Immature Aspects of Thought

Idealism and criticalness Argumentativeness Indecisiveness Apparent hypocrisy Self-consciousness

Imaginary Audience Specialness and Invulnerability

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Changes in Information Processing

Structural: Increases in processing capacity– Expansion of working memory allows

adolescents to deal with complex problems Functional

– Increased ability to obtain, handle and retain information

– Mathematical and scientific reasoning– Improved proficiency in drawing conclusions

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Structural Change inLong-Term Memory

Increase in long-term memory capacity: Declarative knowledge Procedural knowledge Conceptual knowledge

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Language Development

Adolescents can discuss abstractions: Love

Freedom

Justice

Frequently use such terms as: However

Otherwise

Therefore

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Kohlberg’s Levels of Moral Reasoning

Level Stage of Reasoning

Pre-Conventional

Punishment and Obedience

Instrumental Purpose and Exchange

ConventionalApproval of Others: ‘The Golden Rule’

Social Concern and Conscience

Post-Conventional

Contracts, Rights and Democratic Laws

Universal Ethical Principles

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Concerns About Kohlberg’s Theory

Role of family influencesValidity for women and girlsGilligan’s theory: An ethic of careCross-cultural validity

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Influences on School Achievement

Self-efficacy beliefsParenting stylesEthnicityPeer influencesGender

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School Influences on Achievement

What is the quality of the school? Does the student like his/her school? Does the school tailor teaching to

students’ abilities? Does the school help students

transition to college?

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Dropping out of High School

3.8% of high school students dropped out during 2004-2005 school year

Students at greatest risk:– Low SES– Males– Hispanics– Students with low ‘active engagement’

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Factors That PromoteActive Engagement at School

Family encouragementSmall class sizeWarm and supportive school

environmentEarly education programs

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Influences on Students’ Goals

Parental attitudes towards academics Gender and gender-stereotyping The educational system Are schools rewarding creativity?

OR ……..…rote memorization?

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Guiding Non-College-Bound Students

Vocational counselingVocational training programsCommunity collegesOn-the-job training

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