Transcript Document
Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Chapter 5
The Physical Self
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Plasticity: Responsive change to stimulation
• Lack of normal experiences
- Abnormal brain development
- Hubel & Weisel’s kittens
• Stimulating experiences key
• Plasticity greatest at critical period
- Late prenatal, early infancy
- Brain always responsive to stimulation
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Later Brain Development
• Brain grows post-birth
- Birth: 25% of adult weight
- Age 2: 75% of adult weight
- Age 5: 95% adult weight (full weight by 16)
- Mylenation through adolescence
- Dendritic growth (more synapses)
• Lateralization: 2 hemispheres (interdependent)
- Left: language, complex thought
- Right: spatial skills, visual motor, emotions
- Corpus callosum
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
The Infant: Reflexes
• Survival: aid in survival
- Eye-blink
- Rooting
• Primitive: no clear use
- Babinski
- Stepping
- Forerunners of useful voluntary behavior
- Unrelated to later expression of behavior
- Fade in early months
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
The Infant: Behavioral States
• Health = organized/unique pattern
• Sleep-wake pattern key
- By 6 mo: Sleep-wake patterns established
- Birth-6 months 50% sleep is REM
- Regulate sensory stimulation
- Growth (brain)
• Ability to learn
- Operant conditioning
- Sucking increases to sweet taste
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Growth in Infancy
• Fits and starts (no steady)
- First few months 1 ounce/day, I inch/month
- By age 2: About 1/4 adult height
- Inadequate nutrition = growth retardation
- Catch-up growth
• Principles of Growth
- Cephalocaudal: Head to feet
- Proximodistal: Center out
- Orthogenic: Undifferentiated to differentiated
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Motor Skills in Infancy
• Rhythmic stereotypies key
- Repetitive movements before, not after skill develops
• Dynamic systems approach
- Skills develop over time via self-organization process
- Sensory feedback to movements critical
- Nature (maturation) & Nurture (experience)
• Connected to perceptual-cognitive development
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Growth in Childhood
• Slows down, but is steady
- 2-3 inches height & 5-6 lbs/year
• Large and small muscle control improves
- Better coordination, movement
• Reaction time decreases
• Adaptation to a changing environment
- Hand-eye movements improve
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Adolescence
• Physical growth spurt
- Triggered by hormones
- Gender differences
- Earlier for girls
- Boys: more lean muscle, girls more fat
• Puberty (primary & secondary sexual characteristics)
- Gender differences
- Menarche (average 12.5 year)
- Semenarche (average 13)
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Figure 5.7a
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Figure 5.7b
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Variations in Timing (early & late development)
• Causes
- Genetic differences
- Environmental influences
- Secular trend
- Nutritional status
- Family stress
• Psychological implications
- Early easier for boys than girls
- Late easier for girls than boys
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Psychological implications
•
Girls have poorer body images
- Body fat, cultural myths contribute to negative body image for
many young women
•
Boys have more positive views of their changing bodies
- 62% view semenarche positively v. 23% girls & menarche
•
•
Puberty often leads to increased independence, conflict
Early v. late development (differences fade over time)
- Early easier for boys than girls
- Girls can develop problematic behavior from older peers
- Late easier for girls than boys
- Boys tend to be more anxious, less confident/athletic
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Adolescent Physical Behavior
• Noticeable increases in strength
- Continues for boys
- Levels off for girls
• Biological differences: Advantages for boys
• Gender-role socialization
- If athletic, advantages for girls
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Adulthood
• Aging steady but not apparent before 40s
- Hair & skin changes, weight gain
• Weight and muscle loss in the 60’s
- Sedentary lifestyle
- Low education levels
• Osteoporosis: Calcium, exercise
• Osteoarthritis
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Adulthood: Functioning & health
• Physiological systems decline from 20s
- Wide individual differences
- Exercise combats decline
- Reserve capacity
• Changes not universal
- Vast majority of older adults retain adequate function
- 70 or older: 88% men 82% women can walk 1/4 mile
- 92% men 88% women can climb 10 stairs w/o rest
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Adulthood: Functioning & health
• Menopause
- Gradual process taking 5-10 years
- Periods more/less frequent & less regular
- Estrogen levels decline
- Lack of ovulation and conception impossible
- Hot flashes key symptom (Psychological disturbance not common)
- HRT: many risks & benefits
• Male Climacteric gradual
- Levels of testosterone declines
- May never be completely infertile
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Aging:Psychological implications
• Ageism internalized
• Majority function independently
• Majority have high sense of well-being,
contentment
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Carol K. Sigelman, Elizabeth A. Rider
Life-Span Human Development, 4th Edition
Chapter 5: The Physical Self
Physical Behavior in Older Adults
• Slowing down
- Balance and strength decline
- Exercise beneficial
• Disease, disuse, and abuse
- Birren study of men age 65-91
- Increased vulnerability to disease
- Use it or lose it
- Abuse in lifestyle
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