Download LIFE-SPAN DEVELOPMENT

Slide 1
A Topical Approach to
LIFE-SPAN DEVELOPMENT
2
Biological Beginnings
John W. Santrock
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 2
Biological Beginnings
• The Evolutionary Perspective
• Genetic Foundations
• Heredity, Environment, and Individual
Differences
• Prenatal Development
• Birth
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 3
The Evolutionary Perspective
The Evolutionary Perspective
• Natural selection and adaptive behavior
– Darwin and his observations
– All organisms must adapt in life
• Evolutionary psychology
– Emphasizes adaptation, reproduction, and
survival of the fittest in shaping behavior
– Evolution explains human behavior
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 4
The Evolutionary Perspective
Evolution and Life-Span Development
• Benefits of evolutionary selection decrease
with age
• Natural selection failures: harmful conditions
and non-adaptive characteristics
• As adults weaken biologically, culture-based
needs increase
• Alternative: ‘bi-directional view’
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 5
The Evolutionary Perspective
Baltes’ view of evolution and culture
across the life span
Fig. 2.2
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 6
The Evolutionary Perspective
Evaluating Evolutionary Psychology
• Remains just one theoretical approach
• Evolution does not dictate behavior
• Biology allows broad range of cultural
possibilities
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 7
Genetic Foundations
The Genetic Process —
Beginning Life As A Single Cell
• DNA and the collaborative gene
– DNA — deoxyribonucleic acid
– Chromosomes — thread-like structures
– Genes — units of hereditary information
• Human Genome Project
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 8
Genetic Foundations
Cells, Chromosomes, Genes, and DNA
Nucleus (center of
cell) contains
chromosomes
and genes
Fig. 2.3
Chromosomes are
threadlike structures
composed of DNA
molecules
Gene: a segment of DNA
(spiraled double chain)
containing the hereditary
code
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 9
Genetic Foundations
The Genetic Process
• Genes and chromosomes
– Meiosis — specialized form of cell
division
– Fertilization — egg and sperm fuse
together
– Genetic variability in the population
– X and Y chromosomes and sex
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 10
Genetic Foundations
Genetic Principles
• Dominant and recessive genes
• Sex-linked genes
– X-linked inheritance for males and females
• Genetic imprinting
– Imprinted gene dominates
• Poly-genetically determined characteristics
– Many genes interact to influence a trait
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 11
Genetic Foundations
How brownhaired parents
can have a
blond-haired
child: the gene
for blond hair is
recessive
B Brown
hair
Blond
b hair
Father
Bb
B B
Mother
Bb
B b
B b
b b
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 12
Genetic Foundations
Genetic Principles
• Chromosome abnormalities
– Down syndrome
• Sex-linked chromosome
abnormalities
– Klinefelter syndrome
– Fragile X syndrome
– Turner syndrome
– XYY syndrome
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 13
Genetic Foundations
Gene-Linked Abnormalities
•
•
•
•
•
PKU: phenylketonuria
Sickle-cell anemia
Cystic fibrosis
Diabetes
Hemophilia
• Genetic disorders can sometimes
be compensated for by other genes
or events
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 14
Genetic Foundations
Reaction Range
• Range of possible phenotypes for each
genotype, suggesting importance of
environment’s restrictiveness or richness
– Canalization—process by which characteristics
take a narrow path or developmental course
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 15
Genetic Foundations
Chromosome and Gene-Linked
Abnormalities
• Down Syndrome — chromosomally
transmitted form of mental retardation
– Caused by extra (47th) chromosome
• Sex-linked Chromosome Abnormalities
– Caused by problems with sex chromosomes
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 16
Genetic Foundations
Sex-Linked
Chromosome Abnormalities
Klinefelter
Syndrome
Males have an extra X chromosome
Fragile X
syndrome
Abnormality in the X chromosome
Turner
syndrome
Females missing an X chromosome
XYY
syndrome
Males have an extra Y chromosome
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Heredity, Environment, and Individual Differences
Slide 17
Behavior Genetics
• Studies influence of heredity and
environment on individual differences
• Studies use twins or adoptees
– Monozygotic and dizygotic twins
– Adoption study: examine behavior and
psychological characteristics
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Heredity, Environment, and Individual Differences
Slide 18
Heredity-Environment Correlations
• In infancy, environment mostly controlled
by parents
• As children age, their experiences extend
more beyond the family’s influence
• Shared environments are analyzed
– Commonalities between children attributed to
heredity-environment interaction
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Heredity, Environment, and Individual Differences
Slide 19
The Heredity-Environment and
Epigenetic Views
Fig. 2.9
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 20
Prenatal Development
The Course of Prenatal Development
• Germinal period: 2 weeks after conception
• Embryonic period: 2 to 8 weeks after
conception
– Three layers form
– Umbilical cord connect to placenta
• Fetal period
– From 2 months after conception to birth
– Trimesters of pregnancy
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 21
Prenatal Development
The three trimesters of prenatal development
0 - 4 weeks
First
trimester
8 weeks
Less than 1/10th of inch long
Less than 1 inch long
12 weeks
3 inches long, wt: 1 ounce
16 weeks
5.5 inches long, wt: 4 ounces
Second
trimester 20 weeks
10-12 inches, wt: ½ -1 lbs
24 weeks
11-14 inches, wt: 1-1½ lbs
28 weeks
14-17 inches, wt: 2½ -3 lbs
Third
trimester 32 weeks
16½ -18 inches, wt: 4-5 lbs
36-38 weeks 19 inches, wt: 6 lbs
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 22
Prenatal Development
Prenatal Diagnostic Tests
• Amniocentesis: samples amniotic fluid
• Ultrasound sonography
• Chorionic villi sampling: small sample
of placenta taken
• Maternal blood test
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 23
Prenatal Development
Teratogens and the Prenatal
Environment
• Teratogen: agent causing birth defects
• Severity of damage affected by
– Dose
– Genetic susceptibility
– Time of exposure
• Effects of prescription and
nonprescription drugs
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 24
Prenatal Development
Teratogens and Timing of Their Effects on
Prenatal Development
Fig. 2.11
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 25
Prenatal Development
Teratogens and the prenatal
environment
• Psychoactive drugs
– Alcohol and fetal alcohol syndrome (FAS)
– Nicotine’s link to SIDS, ADHD, low birth weight
– Effect of father’s smoking
– Cocaine, marijuana, and heroin
• Environmental hazards and pollutants
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 26
Prenatal Development
Teratogens and the prenatal
environment
• Infectious diseases (AIDS and STDs)
• Incompatible blood types of parents
– Rh-positive and Rh-negative
• Other prenatal factors
– Nutrition, prenatal education and care
– Age of parents
– Maternal emotional states and stress
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 27
Birth
The Process of Birth
• Stages of birth: occurs in three stages
– Uterine contractions
– Baby’s head moves through birth canal
– Afterbirth when placenta, umbilical cord, and
other membranes are detached and expelled
• Baby must withstand stress of birth
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 28
Birth
Strategies for Childbirth
• Deciding what setting, who attends, and
what technique will be used
• Home delivery, birthing center, or hospital?
• 99% of all U.S. births occur in hospitals
• Home births more common outside U.S.
• Role of midwife, nurse, and physician
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 29
Birth
Methods of Delivery
• Medication with analgesics (epidural block,
oxytocics, etc.)
• Possible effects of drugs on fetus
• Natural childbirth
• Prepared childbirth and the Lamaze method
• Cesarean sections for breech babies, other
risks and benefits
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 30
Birth
Neonatal Health and Responsiveness
• Low birth weight infants in U.S. and world
– Weigh less than 5.5 lbs
– Very low birth weight: less than 3 lbs
– Preterm infants: 35 or fewer weeks after
conception (about 12% of U.S. births)
– Small-for-date infants: weigh less than they
should
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 31
Birth
Neonatal Health and Responsiveness
• Consequences of low birth weight
– Low brain weight and risk of brain injury
– Lung and liver disease
– ADHD and learning problems/disabilities
– Breathing problems and asthma
– Lower achievement levels
• Some effects can be reversed
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 32
Birth
Assessing the Newborn
• Apgar Scale: heart, reflexes, and color
• Brazelton Neonatal Behavioral
Assessment Scale (BNBAS)
– A sensitive index of neurological competence
– Four categories in global terms
• Neonatal Intensive Care Unit Network
Neurobehavioral Scale (NNNS)
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Birth
Slide 33
The Apgar Scale
Fig. 2.14
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 34
Birth
Tiffany Field’s Research on
Massage Therapy
• Massage therapy led to 47% greater weight
gain for preterm infants
• Also demonstrated benefits of massage for
– Labor pain
– Asthma
– ADHD
– Arthritis
– Autistic children
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 35
Birth
Weight Gain Comparison of Premature Infants Who
Were Massaged and Not Massaged
Fig. 2.13
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 36
Birth
Bonding
• Needs to occur shortly after birth
• Early emotional attachments may create
healthy interactions after leaving hospital
• Rooming-in arrangements offered
• Massages and tactile stimulation for
premature infants affect development
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Slide 37
2
The End
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.