Transcript LIFE-SPAN DEVELOPMENT

Slide 1
14
Physical Development in
Adolescence
John W. Santrock
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 2
Socioemotional Development
in Adolescence
• What Is the Nature of Adolescence?
• What Are the Physical and Psychological
Aspects of Puberty?
• What Are the Dimensions of Adolescent
Sexuality?
• How Can Adolescent Health and Problems
Be Characterized?
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Is the Nature of Adolescence?
Slide 3
Views of Adolescence
• Positive and Negative Views
– Biological view: Hall’s view – adolescence
is a turbulent time of “storm and stress”
– Adolescence, like childhood, is interaction
of genetic, biological, environmental, and
social factors
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Is the Nature of Adolescence?
Slide 4
What Is the Nature of
Adolescence?
• Recent research:
– Majority can cope with life stresses
– Public attitudes on adolescence affected by
personal experiences, their memories, media
– Every generation seemed radical, different
• Adolescent path to adulthood affected by
– Ethnicity, culture, gender, SES
– Age and lifestyle differences
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Is the Nature of Adolescence?
Slide 5
What Is the Nature of
Adolescence?
• Developmental transitions
– Biological changes
• Growth spurt and hormonal changes
• Sexual maturity and puberty
• Brain maturation and altered sleep patterns
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Is the Nature of Adolescence?
Slide 6
What Is the Nature of
Adolescence?
• Developmental transitions
– Cognitive changes
• Increased abstract, idealistic, logical thinking
• Increased egocentric perceptions
• More responsibility given by parents
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Is the Nature of Adolescence?
Slide 7
What Is the Nature of
Adolescence?
• Developmental transitions
– Socioemotional changes
• Increased independence and time spent with
peers; more conflict with parents
• More mood swings, sexual maturation, and
romantic relationships; more intimacy and
self-disclosure occurs
• Larger, impersonal schools; more pressure to
academically achieve
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Is the Nature of Adolescence?
Slide 8
What Is the Nature of
Adolescence?
• Developmental transitions
– Adolescence to adulthood
• Emerging adulthood: 18 to 25 years
– Identity exploration; love and work
– Instability; changes
– Self-focused
– Feeling in-between
– The age of possibilities
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 9
Determinants of Puberty
• Sexual maturation, height, and weight
– Puberty:
• Period of rapid physical maturation; hormonal
and bodily changes over time
– Menarche: girl’s first menstrual period
– Girls: growth spurt 2 years earlier than boys
– Height increases 3 to 4 inches per year for
boys and girls through growth spurt
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 10
Sexual Maturation
Male
Female
– Increase penis and
testicle size
– Pubic hair growth
– First ejaculation
– Maximum growth
– Hair in armpits
– Voice change
– Facial hair
– Breasts enlarge or
pubic hair appears
– Hair in armpits
– Growth in height
– Hips widen
– First menstruation
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 11
Hormonal Changes
• Hormones
– Powerful chemical substances
– Secreted by endocrine glands
• Hypothalamus: monitors eating, drinking,
and sex
• Pituitary gland: controls growth, regulates
other glands
• Gonadotropins: stimulate ovaries/testes
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 12
Hormonal Changes
• Hormones
– Testosterone associated with male
development of genitals, increased height,
and voice change
– Estradiol associated with female breast
development, uterine, and skeletal
development
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 13
Timing and Variations
in Puberty
• Patterns
– U.S. children mature faster than Europeans
– Age of maturity continually decreases
– Timing changes due to
•
•
•
•
Genetics
Nutrition
Health and females’ body mass
Environmental factors
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
Median Ages at Menarche in Selected Northern European Slide 14
Countries and the United States from 1845 to 1969
Median age (years) at menarche
18
17
16
Norway
Finland
Sweden
U.K.
U.S.A.
15
14
13
12
1840 1860 1880 1900 1920 1940 1960 1980
Year
Fig. 14.4
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 15
Psychological Dimensions
of Puberty
• Hormones and behavior
– Linked to negative, variable emotions
• Body image
– Strong preoccupation with changing
body; more acute in puberty
– Girls more negative than boys
– Use of tattooing, piercing, and body art
• Early and late maturation
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 16
Early and Late Maturation
Girls
• Risk of school,
substance, eating,
Early sex problems
• More independent
Late
• Early body
dissatisfaction,
happier later
Boys
• Positive selfperception
• Successful peer
relations
• Stronger sense
of identity in 30s
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
Early- and Late-Maturing Adolescent Girls’ Perceptions
of Body Image in Early and Late Adolescence
Slide 17
Early development
Late development
Body Image Score
+.30
+.20
+.10
Mean
-.10
-.20
-.30
Grade 6
Grade 10
Fig. 14.5
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Physical and Psychological Aspects of Puberty?
Slide 18
The Brain
• Brain structure, Cognition, and Emotion
– Corpus callosum: activity during emotional
processing differs in adolescents and adults
• Prefrontal lobe not fully developed, amygdala
matures earlier
• Adolescent difficulty in controlling behavior
• Myelination continues in adolescence; thicker
white matter; neuron create gray matter
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 19
Developing a Sexual Identity
• Adolescence is time of
– Ambivalence: sex used in movies/videos/TV
shows/music, advertisements, and Internet
– Frequent viewing tied to casual sex attitudes
– Mastering sexual feelings and forming sense
of sexual identity is lengthy, multifaceted
– Gay and lesbian youth have diverse patterns
of initial attraction, often bisexual.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 20
Developing a Sexual Identity
• Progression of sexual behavior
– Kissing, then petting
– Oral sex or intercourse
– Timing of experiences affected by
• Country, gender, and SES characteristics
– Dramatic increase in casual oral sex
• Perceptions of being safer, not really sex
– Early sexual activity has risks
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 21
Developing a Sexual Identity
– Adolescent males more likely to report
being sexually active than females
– Culturally: Asian Americans have more
restrictive timetable for sexual activity
– African-American males and inner-city
adolescents more sexually active; risk
factors exist and sexual problems
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 22
Contraceptive Use
• Contraceptive use increasing
– Condoms: 63% of males at first intercourse
– Only 19% withdraw before ejaculation
– Low-income females’ use is inconsistent;
may desire pregnancy; more sex partners
• Younger adolescents less likely to use
– Higher risk of pregnancy and disease
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 23
Sexually Transmitted
Infections (STIs)
• HIV and AIDS – greatest impact in world,
girls 6x infection rate of boys in Africa
• Other STDs: chlamydia, gonorrhea,
syphilis, genital herpes
• About 25% of sexually active
adolescents are new infections annually
• Highest risk: drug users, poor, young
gays, Latinos and African Americans
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 24
Adolescent Pregnancy
• U.S. rates declining but still one of
highest in industrialized world
– Fear of STIs, use of condoms
– Why?
• Childbearing regarded as adult activity
• Clear messages about sexual behavior
• Access to family planning services
• U.S. expectations and attitudes more lax, yet
access to planning services more restricted
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
Cross-Cultural Comparisons of
Adolescent Pregnancy Rates
Slide 25
Births per 1000 women 15 to19
80
U.S.
England and
Wales
Canada
60
France
40
Sweden
20
0
1970 1975 1980 1985 1990 1995 2000
Year
Fig. 14.8
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
What Are the Dimensions of Adolescent Sexuality?
Slide 26
Reducing Adolescent
Pregnancy
• Sex education and family planning
• Access to contraceptives
• Life options approach
– Opportunities other than parenting
• Broad community involvement, support
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 27
Adolescent Pregnancy
• Ethnic, SES factors affect rates vary
• Risk factors
– Health problems for baby and mother
– Low education for mothers
– Economic hardships
– Educational, behavioral problems for
children
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 28
Adolescent Health
• Improving adolescent health
– Increase healthy behaviors
• Nutrition, exercise, safety, sleep patterns
– Reduce risky behaviors
• Drug abuse, violence
• Unprotected sex, risks for accidents
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 29
Adolescent Health
• U.S. youth compared to most in world
– Eat more junk food
– Eat less fruits and vegetables
– Exercise less and more inactive
• Ethnic differences: white boys exercised
most; African American girls exercised least
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 30
Adolescent Health
• U.S. youth
– Get inadequate sleep on weekdays; stay up
later, sleep longer in morning
– Affects on school: moody, tired, sleep in
class, depressed, drink more caffeine
– Attempts to make up sleep deficit on
weekends
– Changing biological clocks: melatonin
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 31
Adolescent Health
• Leading causes of death
– Accidents: over 50% of death ages 10–19
• Most due to motor vehicles and risky behaviors
like speeding, use of drugs or alcohol
– Homicide: second leading cause, especially
among African American males
– Suicide: 6% of ages 10–14 and 12% of
ages 15–19
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 32
Adolescent Health
• Risk factors that predict problems
– Poverty
– Ineffective parenting
– Mental disorders in parents
• Assets for positive outcomes
– External: support, empowerment, rules, etc.
– Internal: commitment, values, positive
identity, and social competencies, etc.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 33
Substance Use and Abuse
• Alcohol
– Drinking habits begin in high school, college
• Cigarette smoking
– Begins primarily in childhood, adolescence
• Painkillers
– Alarming increased use of prescriptions
• Narcotic and addictive; abuse may be epidemic
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 34
Substance Use and Abuse
• Risk factors for abusing prescription
painkillers
– Prior use of illicit drugs
– Low-SES family background
– Favorable attitudes toward illicit drugs
– Detached parents
– Friends who use drugs
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 35
Substance Use and Abuse
• Roles of development
– Most adolescents use drugs at some point
in their development
– Use of drugs to cope with stress; long-term
detrimental effects
– Early use may predict use in adult life
– Parents, peers, and social support can play
important roles in prevention
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 36
Trends in Drug Use by U.S. 8th-, 10th-, and
12th-Grade Students
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 37
Eating Problems and Disorders
• Becoming more common
– Obesity
• Ages 12–19: obesity increased to 17%
• Ethnic variations exist: African American girls
and Latino boys at higher risk
• Few cross-cultural comparisons done
– Interventions
• Balanced diet, exercise, behavioral therapy
• School changes: programs, foods available
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 38
Eating Problems and Disorders
• Anorexia Nervosa
– Eating disorder, relentless to be thin through
starvation; serious, can lead to death
– Main characteristics
• Weighing less than 85% of normal weight
• Having intense fear of gaining weight
• Having distorted image of one’s body shape
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 39
Eating Problems and Disorders
• Anorexia Nervosa
– Begins in teen years
• mostly white, female, well-to-do families
• Unable to meet high expectations, competition
– Influenced by fashion industry and media
• Bulimia Nervosa
– Eating disorder with binge-and-purge
pattern of eating, use of laxatives
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
How Can Adolescent Health And Problems Be Characterized?
Slide 40
Eating Problems and Disorders
• Bulimia Nervosa
– Like anorexics: preoccupied with food, fear
of being overweight, depressed or anxious
– 90% are women
– Begins in late adolescence, early adulthood
– About 70% eventually recover
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 41
14
The End
© 2009 The McGraw-Hill Companies, Inc. All rights reserved.