Development
Through the Lifespan
Chapter 11
Physical and Cognitive
Development in
Adolescence
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Conceptions of Adolescence
 Biological Perspective
 Puberty
 Storm and stress
 Freud – genital stage
 Social Perspective
 Social and cultural influences
 Balanced Point of View
 Both biological and social influences
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Three Phases of Adolescence
Early
Middle
Late
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11-12 to
Rapid pubertal change
14 years
14 to 16
Puberty nearly complete
years
16 to 18  Full adult appearance
years  Anticipation of adult roles
Hormonal Changes in Puberty
 Growth Hormone and Thryoxine
increase around age 8 – 9
 Estrogens
 More in girls
 Adrenal estrogens
 Androgens
 More in boys
 Testosterone
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Sex Differences in
Body Growth in Adolescence
Boys
Girls
Starts age 12-1/2
Starts age 10
Hips broaden
Proportions
Shoulders broaden
Longer legs
Muscle-Fat
Makeup
Gain more muscle,
aerobic efficiency
Gain more fat
Growth Spurt
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Sports Participation
in High School
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Sexual Maturation
Primary Sexual
Characteristics
Secondary Sexual
Characteristics
 Other visible parts of the
 Maturation of the
body that signal sexual
reproductive organs
maturity
 Girls: menarche
 Boys: spermarche
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 Girls: breasts
 Boys: facial hair,
voice change
 Both: underarm hair
Individual Differences in
Timing of Puberty
 Heredity
 Nutrition, exercise
 Body fat, leptin in girls
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Geographical location
SES
Ethnic group
Family experiences
Secular trend
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Adolescent Brain Development
Pruning
continues
Growth &
myelination
speed up
Frontal lobes
Strengthen
connections
among regions
More sensitive
Neurotransmitter
to excitatory
response changes
messages
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Cognitive advances:
 Attention
 Planning
 Integrating
information
 Self-regulation
Intensifies reactions to
 Stress
 Pleasure, novelty
Sleep Habits in Adolescence
 Still need almost as much sleep,
but go to bed later
 Biological “phase delay”
 Social habits
 Lack of sleep impairs regulation
of attention, emotion
 Lower achievement
 Mood problems
 High-risk behavior
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Reactions to Puberty
Girls
Boys
 Surprise
 More positive
than in past
 Mixed reactions  Preparation helps
 Could benefit from
 Sooner than
expected
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 Preparation,
information help
Father’s
involvement helps
telling people
Adolescent Moodiness
 More negative life events
 Stronger responses
 Moods swings
 Related to daily events
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Adolescent Emotions
Across the Week
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Parent-Child Relationships
During Adolescence
 Rise in conflict
 Psychological distancing
 Different views of teen readiness for
responsibility
 Most conflict is mild
 Also affection, support
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Consequences of
Timing of Puberty
Girls
Boys
Early
Maturing
• Unpopular, withdrawn,
low confidence
• More deviant behavior
• Negative body image
• More long-term problems
• Popular
• Confident, independent
• Positive body image
Late
Maturing
• Popular
• Sociable, lively. school
leaders
• Positive body image
• Unpopular
• Anxious, talkative,
attention-seeking
• Negative body image
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Factors in Reactions
to Timing of Puberty
 Physical attractiveness – body image
 Girls: most want to be
thinner, smaller
 Boys: most want to be bigger
 Fitting in with peers
 Prefer similar level
of physical maturity
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Nutrition in Adolescence
 Calorie needs increase
 Poor food choices common
 Less fruits, vegetables, milk, breakfast
 More soda, fast food
 Iron, vitamin deficiencies
 Eating with family can help
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Eating Disorders
 Anorexia nervosa
Starve out of fear
of getting fat
 Bulimia nervosa
Strict diet and exercise,
binge and purge
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Adolescent Sexuality
 North American attitudes relatively restrictive
 Media contradicts family messages
 Abstinence programs
 More liberal over past 40 years
 Most say premarital sex
OK for committed partners
 Activity matches attitudes
 Rates declining since 1990s
 Few partners
 Americans more than Canadians
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Talking to Adolescents
About Sex
 Foster open communication
 Use correct terms
 Listen, discuss, collaborate
 Think before talking
 Keep conversations going
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Percentages of Girls
Who Have Had Sex
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Adolescent Contraceptive Use
 Recent increase in
contraceptive use
 Still, 27% American, 13%
Canadian do not use
 Reasons for not using:
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Concern about image
Adolescent risk taking
Social environment
Forced intercourse
Characteristics of
Sexually Active Adolescents
Personal
Family
Peer
Educational
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• Early puberty
• Tendency to violate norms
• Little religious involvement
• Step, single-parent, or large family
• Weak parental monitoring, parent-child
communication
• Sexually active friends or siblings
• Poor school performance
• Low educational goals
Sequence of Coming Out
 Feeling Different
ages 6–12
 Confusion
ages 11–15
 Acceptance
timing varies
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Most Common STDs
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AIDS
Chlamydia
Cytomegalovirus
Genital warts
Gonorrhea
Herpes simplex 2
Syphilis
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Adolescent Pregnancy Statistics
Teens pregnant each year U.S. - 900,000
(30,000 under age 15)
Canada - about 450,000
Percent of teen
40% - U.S.
pregnancies ended with
50% - Canada
abortion
Percent of teen mothers
85%
who are unmarried
Repeat teen births
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20%
Risks for Teen Mothers
 Less educational achievement
 More time as single parents
 Economic problems
 Pregnancy and birth
complications
 Lack of parenting skills
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Pregnancy Rates
Among 15- to 19-Year-Olds
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Help for Teen Pregnancy
Prevention Strategies
 More sex education
 Skills for handling sexual
situations
 Promoting abstinence
 Info. & access to
contraceptives
 Academic & social
competence
 School involvement
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Intervention with
Teenage Parents
 Health care
 Help staying in school
 Job & life-management
training
 Parenting instruction
 Child care
 Adult mentors
 Father support
Adolescent Substance Use
 Have tried, by grade 10:
 Cigarettes – 40%
 Alcohol – 63%
 Illegal drugs – 38%
 By end of high school:
 14% smoke regularly
 28% recent heavy drinking
 50%+ tried illegal drugs
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Adolescent Substance Abusers
Compared to experimenters
 More antisocial, impulsive acts
 Start earlier
 More likely to be affected by
genetic and environmental
factors
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Piaget’s Theory:
Formal Operational Stage
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Hypothetico-deductive reasoning
Deducing hypotheses from a general theory
 Pendulum problem
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 Propositional Thought
 Evaluating the logic of verbal propositions
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Piaget’s Pendulum Problem
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Follow-up Research on
Formal Operational Thought
 School-age children start developing abstract
thinking skills
 Problems with propositional thinking
 Logical necessity
 Formal operations may not be
universal
 Training, context contribute
 Often fall back on easier thinking
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Information Processing
Improvements in Adolescence
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Attention
Inhibition
Memory strategies
Knowledge
Metacognition
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 Cognitive selfregulation
 Processing capacity
 Speed of thinking
Scientific Reasoning
 Coordinating Theory with Evidence
 Improves with Age
 From childhood through adulthood
 Individuals vary
 Contributing factors
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Working memory capacity
Exposure to complex problems
Metacognitive understanding
Open-mindedness
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Scientific Reasoning Task
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Consequences of
Abstract Thought
 Self-Consciousness & Self-Focusing
 Imaginary audience
 Sensitivity to criticism
 Personal fable
 Idealism and Criticism
 Planning and Decision Making
 Inexperience
 Overwhelming options
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Sex Differences in Mental Abilities
Skill
Verbal
Math
Performance
Biological Influences
Environmental
Influences
Girls do better from Girls: advantage in
early ages,
left hemisphere of
throughout school
brain
Parents talk more
to girls
Language arts
considered
“feminine”
 Boys better at
abstract reasoning
 Gap larger at
higher levels,
although shrinking
Mathematics
considered
“masculine.”
 Parents see boys
as better at math
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Boys: better
numerical memory,
spatial reasoning
Gender Differences in
Reading and Writing
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School Transitions
in Adolescence
 Grades decline with each
transition
 Higher standards
 Less supportive teachinglearning environment
 Lower self esteem
 More with 6 – 3 – 3
organization than 8 – 4
 Girls more than boys
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School Transitions
and Students with Problems
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Helping Adolescents
Adjust to School Transitions
 Parental involvement, monitoring
 Smaller units within schools
 Homeroom teacher
relationships
 Classes with familiar peers
 Minimize competition,
treatment by ability at school
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Supporting
Academic Achievement
 Child-rearing practices
 Peer influences
 Value high achievement
 Authoritative
 Employment schedule
 Joint decision making
 Vocational education
 Parent-school partnerships
 School characteristics
 Classroom learning
experiences
 Teaching
 Tracking
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High School Graduation Rates
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Drop-Out Rates
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Dropout Prevention Strategies
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High-quality vocational training
Remedial instruction
Personalized counseling
Address factors in
students’ lives outside
school
 Extracurricular
activities
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Benefits of
Extracurricular Activities
 Academic performance
 Social skills, peer acceptance
 Self esteem, confidence
 Less antisocial behavior
 Improved family
relationships
 Higher achievement later in
life
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