1. Slide 1 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. LIFE-SPAN DEVELOPMENT 2 A Topical Approach to John W. Santrock Biological Beginnings

2. Slide 2 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Biological Beginnings The Evolutionary Perspective Genetic Foundations Heredity, Environment, and Individual DifferencesHeredity, Environment, and Individual Differences Prenatal Development Birth

3. Slide 3 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 The Evolutionary Perspective

4. Slide 4 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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’ The Evolutionary Perspective

5. Slide 5 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. The Evolutionary Perspective Fig. 2.2 Baltes’ view of evolution and culture across the life span

6. Slide 6 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Evaluating Evolutionary Psychology Remains just one theoretical approach Evolution does not dictate behavior Biology allows broad range of cultural possibilities The Evolutionary Perspective

7. Slide 7 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Genetic Foundations

8. Slide 8 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Cells, Chromosomes, Genes, and DNA Genetic Foundations Nucleus (center of cell) contains chromosomes and genes Chromosomes are threadlike structures composed of DNA molecules Gene: a segment of DNA (spiraled double chain) containing the hereditary code Fig. 2.3

9. Slide 9 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. The Genetic Process Genetic Foundations 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

10. Slide 10 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Genetic Principles Genetic Foundations 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

11. Slide 11 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Genetic Foundations b B b B b B Blond hair Brown hair How brown- haired parents can have a blond-haired child: the gene for blond hair is recessive Mother B b Father B b

12. Slide 12 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Genetic Foundations Genetic Principles Chromosome abnormalities –Down syndrome Sex-linked chromosome abnormalities –Klinefelter syndrome –Fragile X syndrome –Turner syndrome –XYY syndrome

13. Slide 13 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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

14. Slide 14 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Genetic Foundations

15. Slide 15 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Genetic Foundations

16. Slide 16 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Sex-Linked Chromosome Abnormalities Genetic Foundations Klinefelter Syndrome Fragile X syndrome Turner syndrome Males have an extra X chromosome Abnormality in the X chromosome Females missing an X chromosome XYY syndrome Males have an extra Y chromosome

17. Slide 17 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Heredity, Environment, and Individual Differences

18. Slide 18 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Heredity, Environment, and Individual Differences

19. Slide 19 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. The Heredity-Environment and Epigenetic Views Heredity, Environment, and Individual Differences Fig. 2.9

20. Slide 20 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Prenatal Development

21. Slide 21 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Second trimester Third trimester First trimester 0 - 4 weeks Less than 1 inch long 12 weeks 32 weeks 8 weeks Less than 1/10th of inch long 16½ -18 inches, wt: 4-5 lbs 3 inches long, wt: 1 ounce 16 weeks 5.5 inches long, wt: 4 ounces 20 weeks10-12 inches, wt: ½ -1 lbs 24 weeks11-14 inches, wt: 1-1½ lbs 36-38 weeks 28 weeks 19 inches, wt: 6 lbs 14-17 inches, wt: 2½ -3 lbs The three trimesters of prenatal development Prenatal Development

22. Slide 22 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Prenatal Diagnostic Tests Amniocentesis: samples amniotic fluid Ultrasound sonography Chorionic villi sampling: small sample of placenta taken Maternal blood test Prenatal Development

23. Slide 23 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Prenatal Development

24. Slide 24 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Prenatal Development Fig. 2.11 Teratogens and Timing of Their Effects on Prenatal Development

25. Slide 25 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Prenatal Development

26. Slide 26 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Prenatal Development

27. Slide 27 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

28. Slide 28 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

29. Slide 29 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

30. Slide 30 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

31. Slide 31 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

32. Slide 32 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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) Birth

33. Slide 33 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Birth Fig. 2.14 The Apgar Scale

34. Slide 34 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

35. Slide 35 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. Birth Fig. 2.13 Weight Gain Comparison of Premature Infants Who Were Massaged and Not Massaged

36. Slide 36 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. 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 Birth

37. Slide 37 © 2007 The McGraw-Hill Companies, Inc. All rights reserved. The End 2