1. Chapter 11 Physical and Cognitive Development in Adolescence

2. Conceptions of Adolescence
There are two main perspectives
Biological perspectives
Social Perspectives
Biological perspective-Stanley Hall viewed adolescence from a “storm and stress” perspective
He described adolescence as a period so turbulent that it resembled the era in which humans evolved from savages into civilized beings
Social Perspective- Margaret Mead According to Margaret Mead, the social environment is entirely responsible for the experiences of teenagers Now we know that biological, psychological and social forces combine to influence adolescent development

3. Hormonal Changes in Puberty
Estrogens are female hormones
Androgens are male hormones
Estrogens and Androgens are present in each sex but in different amounts
Boys release large quantities of testosterone which leads to muscle growth, body and facial hair
Estrogens are released by girls and this causes the breast and uterus to mature
Estrogens also contribute to regulation of the menstrual cycle
Adrenal androgens released from the adrenal glands on top of each kidney, influences girl’s height spurt

4. Body Growth in Adolescence
The first sign of puberty is the rapid gain in height and weight
For girls this happens shortly after the age of 10
For boys this happens around the age of 12 and a half
Girls are typically taller and heavier during early adolescence
At the age of 14 boys begin to grow taller
At the age of 16 most girls stop growing and for boys they stop growing at the age of 17 and a half
Large sex differences in body proportions appear
Boys shoulder broadens
Girls hips broaden
Boys end up being larger than girls and their legs are longer
Around age 8 girls start to add fat on their arms, legs and trunk
In contrast, arm and leg fat decreases in boys
Although both sexes gain muscles, this increase is much greater in boys

5. Sexual Maturation Primary Sexual Characteristics
Maturation of the reproductive organs (ovaries, uterus, scrotum…)
Menarche is the first menstruation in girls (12 and a half)
Spermarche (first ejaculation around 13 and a half)
Secondary Sexual Characteristics
Other visible parts of the body that signal sexual maturity
Girls: breasts
Boys: facial hair, voice change
Both: underarm hair

6. Individual Differences in Puberty Growth
Heredity contributes to the timing of pubertal changes
Identical twins are more similar than fraternal twins in attaining puberty milestones
Nutrition and exercise also makes a difference
Girls who begin rigorous athletic training at an early age or who eat very little usually experience later puberty
In poverty-stricken regions where malnutrition and infectious disease are common, menarche is greatly delayed
Research indicates that girls and boys with a history of family conflict, harsh parenting styles, or parental separation tend to reach puberty early.
In contrast those with warm, stable family ties reach puberty relatively late.

7. What changes in the brain take place during adolescence?
Pruning of unused synapses in the cerebral cortex continues
Linkages between areas of the brain expand and myelinate
As the prefrontal cortex becomes a more effective, adolescents gradually gain in processing speed and executive function
During poverty neurons become more responsive neurotransmitters
This increases emotional reactivity
Changes in the brain’s emotional or social network does result in self regulation difficulties

8. Sleep Habits in Adolescence
Still need almost as much sleep, but go to bed later
Lack of sleep impairs executive function:
reduced achievement
increased anxiety, depressed mood
high-risk behaviors

9. Reactions to Pubertal Changes
Girls who have no information, menarche can be shocking and disturbing
Today, few girls are uninformed because parents are willing to discuss sexual matters and to spread health education classes
Boys responses to spermache reflect mixed feelings
Most boys know about ejaculation but say that no one talked to them before or during puberty about physical changes
Boys usually get their information from reading material or websites
Overall boys get less social support than girls
Preparation, information helpful
Boys and girls could benefit from more social support

10. Adolescent Moodiness
Teenagers with supportive families and peer relationships less often report negative moods than their age mates with few social supports
Poorly adjusted young people with low self esteem often express intense negative emotions

11. Parent-Child Relationships
Parent-daughter conflicts tends to be more intense than conflict with sons because it is possible that parents place more restrictions on girls
Parents and teenagers display both conflict and affection

12. Consequences of Pubertal Timing
Girls
Boys
Early Maturing
Unpopular, withdrawn, low in confidence
Less positive body image
More deviant behavior
Prone to lasting difficulties
Popular
Self-confident, independent
More positive body image
Late Maturing
Sociable, school leaders
Unpopular
Anxiety, depressed mood

13. Nutrition in Adolescence
Poor food choices common:
skipping breakfast
eating fast foods
Family meals associated with healthier diet

14. Eating Disorders Anorexia Starve self due to fear of getting fat
Equally common across SES groups
Racial/ethnic variations
Heredity, neurotransmitter abnormalities, parenting style, and personal/cultural factors contribute
Difficult to treat
Bulimia Nervosa
Strict dieting, excessive exercise, and purging
Heredity, parenting style, and personal/cultural factors contribute
More common and easier to treat than anorexia

15. Adolescent Sexuality Turn to page 297
What does your textbook say about sexuality?
Sexual attitudes in North America are relatively restrictive
Parents provide little or no information about sex, discourage sex play and rarely talk about sex in the presence of children.
Many parents avoid meaningful discussions about sex out of fear of embarrassment or concern that the adolescent will not take them seriously. Adolescents who do not get information about sex from parents are likely to learn from friends, books, magazines, movies, TV, and the internet.

16. Characteristics of Sexually Active Adolescents
Personal
Early pubertal timing
Childhood impulsivity
Weak sense of personal control
Family
Step-, single-parent, or large family
Little or no religious involvement
Weak parental monitoring, disrupted parent–child communication
Peer
Sexually active friends and older siblings
Alcohol, drug use
Educational
Poor school performance
Low educational goals

17. Adolescent Contraceptive Use
20% of U.S. sexually active teenagers do not use contraceptives consistently
Reasons:
social environment: lack of meaningful education and work
unrealistic about consequences
sexual exploitation

18. Sexual Orientation
About 4% of year old U.S. citizens identify themselves as lesbian, gay or bisexual
Heredity plays an important role by contributing to homosexuality
Identical twins of both sexes are more likely than fraternal twins to share a homosexual orientation and so are biological relatives
How might heredity lead to homosexuality?
According to research, certain genes affect the level of impact of prenatal sex hormones, which modify brain structures in ways that induce homosexual feelings and behavior

19. Sexual Orientation
Environmental factors can also alter prenatal hormones.
Girls who are exposed to very high levels of androgens or estrogens either because of a genetic defect or from drugs given to the mother to prevent miscarriage are more likely to become lesbian
Gay men tend to be later in birth order

20. Adolescents and Sexually Transmitted Diseases
STD rates highest in adolescence:
especially high in United States
1 out of 5 to 6 sexually active teens affected
AIDS most serious:
manifests 8–10 years later
often infected during adolescence
Females more easily infected
STD education improving

21. U.S. Adolescent Pregnancy Statistics
About 727,000 teen pregnancies in most recently reported year
12,000 younger than age 15
1 in 4 end in abortion
87% of births to unwed mothers

22. Factors Contributing to Adolescent Parenthood
Low parental warmth and involvement
Poverty
Domestic violence and child abuse
Repeated parental divorce and remarriage
Poor school achievement
Engage in alcohol and drug use
Antisocial behavior
Experience high rates of depression

23. Risks for Teenage Mothers and Babies
Low educational attainment
More time as single parent
Economic difficulties
Pregnancy and birth complications
Weak parenting skills

24. Teen Pregnancy Prevention and Intervention
Strategies
Better sex education
Skills for handling sexual situations
Information and access to contraceptives
Academic and social competence
School involvement
Intervention
Strategies
Health care
Help staying in school
Job and life-management training
Parenting instruction
Adult mentors
Affordable child care
Father support

25. U.S. Adolescent Substance Use
Have tried, by grade 10:
cigarettes—33%
alcohol—58%
illegal drugs—37%
By end of high school:
11% smoke regularly
27% report recent heavy drinking
25% have used highly addictive drugs

26. Substance Use versus Abuse
Experimenters
Psychologically healthy
Sociable
Sensation-seeking
Abusers
Low SES
Family mental health problems, substance abuse
Child abuse
Impulsivity, hostility
Drug-taking starts earlier

27. Prevention and Treatment
Good school programs
promote effective parenting
teach skills to resist peer pressure
reduce social acceptability of drugs
Interventions to prevent harm
Family and individual therapy

28. Piaget’s Theory: Formal Operational Stage
Hypothetico-deductive reasoning:
problem solving based on a hypothesis, deducing logical, testable inferences
pendulum problem (turn to page 304)
Propositional thought:
evaluating the logic of verbal propositions without using real-world circumstances

29. Follow-Up Research on Formal Operational Thought
School-age children show beginnings of formal operational thought
Adolescents are considerably more competent:
reason about more variables simultaneously
grasp logical necessity
Formal operations may not be universal:
training and context contribute
schooling is powerfully influential

30. Gains in Information Processing: Executive Function
Attention
Inhibition
Strategies
Knowledge
Metacognition
Cognitive self-regulation
Speed of thinking
Processing capacity
What does your textbook say about the following? Page 306

31. Scientific Reasoning
Scientific reasoning focuses on coordinating theory with evidence
Factors that support skill at coordinating theory with evidence
working memory capacity
exposure to complex problems
metacognitive understanding
open-mindedness
Adolescents and adults vary widely in scientific reasoning

32. Consequences of Adolescent Cognitive Changes
Self-consciousness and self-focusing:
imaginary audience- adolescents’ belief that they are the focus of everyone else’s attention
personal fable-teenagers develop an inflated opinion of their own importance, a feeling that they are special and unique
Idealism and criticism (page 308)
Decision making: (page 308)
influenced by immediate reward
fall back on well-learned, intuitive judgments

33. School Transitions in Adolescence
Grades decline with each transition:
higher academic standards
less supportive teaching– learning environment
Drop in self-esteem:
additional strains increase risk

34. Problem Behaviors Across Transition to High School

35. Helping Adolescents Adjust to School Transitions
Parent involvement, monitoring
Close friendships
Smaller units within schools
Same-ethnicity peers
Homeroom teacher relationships

36. Supporting Academic Achievement
Child-rearing practices
Authoritative
Joint decision making
Parent involvement in education
Peer influences
Valuing high achievement
School characteristics
Warm, personal teaching
Classroom learning experiences
Opportunities to break out of low academic tracks

37. Factors Related to Dropping Out
Low grades, low academic self-esteem
No extracurricular involvement
Family background:
uninvolved parenting style
limited parental education
Grade retention
Large, impersonal schools
General education, vocational tracks

38. Dropout Prevention Strategies
Remedial instruction
Personalized counseling
High-quality vocational training
Addressing personal factors related to dropout
Extracurricular participation