Download The Study of Human Development

Physical and Cognitive
Development in Adolescence
Chapter 11
© 2009 by the McGraw-Hill Companies, Inc
1
Guideposts for Study
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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?
© 2009 by the McGraw-Hill Companies, Inc
2
Guideposts for Study

How do adolescents’ thinking and use of
language differ from younger children’s?
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On what basis do adolescents make
moral judgments?
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What factors affect adolescents’ school
success and their educational and
vocational planning and preparation?
© 2009 by the McGraw-Hill Companies, Inc
3
Adolescence and Puberty

Adolescence
The passage from childhood
to adulthood

Puberty
Process that leads to sexual
maturity or fertility
© 2009 by the McGraw-Hill Companies, Inc
4
Adolescence as
Social Construction
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No such concept in preindustrial societies
Today, adolescence is a global phenomenon
Time for growth and change
Stereotypes of risk-taking behaviors
© 2009 by the McGraw-Hill Companies, Inc
5
Box 11.1
Globalization of Adolescence
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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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6
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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7
Physical Changes of Puberty

Both males and females:
–
–
–
–
Growth spurt
Pubic hair
Deeper voice
Muscular growth
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8
Puberty Onset
 Girls
–
Between ages 8 and 10
 Boys
–
Between ages 9 and 11
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9
Primary Sex Characteristics

Females
–
–
–
–
Ovaries
Fallopian tubes
Uterus
Vagina
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Males
– Testes
– Penis
– Scrotum
– Seminal vesicles
– Prostate gland
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Secondary Sex Characteristics

Females
o
o
Breasts
Pelvis changes
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Males
o
o
Broad Shoulders
Facial Hair
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Adolescent Growth Spurt
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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
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Spermarche
–
–
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First ejaculation
Nocturnal emission (wet dream)
Average at age 13
Menarche
–
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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:

–
–
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Higher standard of living/better
nutrition
Overweight
Relationship with father
 Pheromones
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Adolescent Brain
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A “work in progress”
Immaturity of adolescent brain has led to
questions of legal responsibility
Risk taking comes from two brain networks
o
o
Socioemotional network (i.e. peer influence)
Cognitive control network (responses to stimuli)
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Two Major Brain Changes
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Growth Spurt
–
–
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Chiefly in frontal lobes
Reasoning, judgment, and impulse
control
Gray Matter Growth
–
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Continued myelination
Facilitates maturation of cognitive
abilities
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Physical Activity
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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
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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
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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
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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
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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
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Bingeing and undoing of caloric intake on
regular basis
‘Undo’ calories by:
–
–
–
–
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Self-induced vomiting
Excessive exercise
Laxatives or enemas
Diuretics
Dieting or fasting
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Treatment of
Anorexia and Bulimia
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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
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Substance Use
–
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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
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Difficult temperament
Poor impulse control and sensation seeking
Biochemical basis and/or family influence
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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
 Alcohol
 Marijuana
 Tobacco
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Depression
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Prevalence increases during adolescence
Occurs in 9% ages 12-17, only 40% treated
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Girls more susceptible than boys
Can manifest as:
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–
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Sadness
Irritability
Boredom
Inability to experience pleasure
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Causes of Death
in Adolescence
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Vehicular Accidents
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Firearms
–
–
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Leading cause of death among U.S. teens
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
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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
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Problem-solving skills
Developing a hypothesis and an
experiment to test it
Imagining relationships systematically
Piaget attributed acquiring this new skill to:
–
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Brain maturation
Expanding environmental opportunities
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Evaluating Piaget’s Theory
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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
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Idealism and criticalness
Argumentativeness
Indecisiveness
Apparent hypocrisy
Self-consciousness
Imaginary Audience
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Specialness and Invulnerability
Personal Fable
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Changes in
Information Processing
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Structural: Increases in processing
capacity
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Expansion of working memory allows
adolescents to deal with complex problems
Functional
–
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Increased ability to obtain, handle and retain
information
Mathematical and scientific reasoning
Improved proficiency in drawing conclusions
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Structural Change in
Long-Term Memory
Increase in long-term memory capacity:
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Declarative knowledge
Procedural knowledge
Conceptual knowledge
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Language Development
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Adolescents can discuss abstractions:
Love
Freedom
Justice
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Frequently use such terms as:
However
Otherwise
Therefore
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Kohlberg’s Levels of
Moral Reasoning
Level
Stage of Reasoning
PreConventional
Punishment and Obedience
Instrumental Purpose and Exchange
Approval of Others: ‘The Golden Rule’
Conventional
Social Concern and Conscience
PostConventional
Contracts, Rights and Democratic Laws
Universal Ethical Principles
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Concerns About
Kohlberg’s Theory
Role of family influences
 Validity for women and girls
 Gilligan’s theory: An ethic of care
 Cross-cultural validity

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Influences on
School Achievement
 Self-efficacy
beliefs
 Parenting styles
 Ethnicity
 Peer influences
 Gender
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School Influences
on Achievement
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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
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3.8% of high school students dropped out
during 2004-2005 school year
Students at greatest risk:
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Low SES
Males
Hispanics
Students with low ‘active engagement’
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Factors That Promote
Active Engagement at School
Family encouragement
 Small class size
 Warm and supportive school
environment
 Early education programs

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Influences on
Students’ Goals
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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 counseling
 Vocational training programs
 Community colleges
 On-the-job training

© 2009 by the McGraw-Hill Companies, Inc 47