development across the life span

1. 7 development across the life span

2. why study human development?Beginning to understand how we come to be the people we are is a critical step in understanding ourselves as we are today and who we may become as we grow older. From the moment of conception, each of us is headed down a pathway of change, influenced by our biology, environment, and social interactions, to a final destination that is the same for all of us. The twists and turns of the pathway are what make each of us unique individuals. In this chapter, we'll look at the influences that help determine our developmental pathway through life.

3. Learning Objective Menu • LO 7.1 Special research methods used to study development • LO 7.2 Relationship between heredity and environmental factors • LO 7.3 Chromosomes, genes, DNA and multiple births • LO 7.4 Germinal, embryonic, and fetal periods of pregnancy • LO 7.5 Physical changes in infancy and childhood • LO 7.6 Looking at cognitive development and how language develops • LO 7.7 Developing personalities, forming relationships and Erikson’s first four stages of psychosocial development • LO 7.8 How adolescents develop formal operation, moral thinking and adolescent’s search for identity

4. Learning Objective Menu • LO 7.9 Physical and cognitive changes during adulthood and aging • LO 7.10 Theories of why aging occurs and stages of death and dying • LO 7.11 How attention-deficit/hyperactivity disorder affects adults

5. Developmental Research Designs LO 7.1 Special research methods used to study development • Human development • Scientific study of the changes in people • Covers aging from conception until death • Longitudinal design • Participant or group of participants is studied over time

6. Developmental Research Designs LO 7.1 Special research methods used to study development • Cross-sectional design • Different age groups of participants are studied at one particular point in time • Cross-sequential design • Participants are first studied by cross-sectional design • Followed and assessed for a period up to six years

7. Table 7.1 A Comparison of Three Developmental Research Designs

8. Nature versus Nurture LO 7.2 Relationship between heredity and environmental factors • Nature • Influence of inherited characteristics on personality, physical growth, intellectual growth, and social interactions • Nurture • Influence of the environment on personality, physical growth, intellectual growth, and social interactions

9. Nature versus Nurture LO 7.2 Relationship between heredity and environmental factors • Behavioral genetics • Attempts to assess impact of genetics and environment

10. Genetics and Development LO 7.3 Chromosomes, genes and DNA and multiple births • Genetics • The science of heredity • DNA (deoxyribonucleic acid) • Basic building blocks of life • Gene • Instructions • Are sections of DNA

11. Genetics and Development LO 7.3 Chromosomes, genes and DNA and multiple births • DNA (deoxyribonucleic acid) • Dominant • Gene actively controls the expression of a trait • Example: Huntington’s and Marfan’s disorders

12. Genetics and Development LO 7.3 Chromosomes, genes and DNA and multiple births • DNA (deoxyribonucleic acid) • Recessive • Trait is expressed when passed from both parents • Example: Tays-Sachs disorder and Phenylketonuria (PKU)

13. Figure 7.1 DNA MoleculeIn this model of a DNA molecule, the two strands making up the sides of the “twisted ladder” are composed of sugars and phosphates. The “rungs” of the ladder that link the two strands are amines. Amines contain the genetic codes for building the proteins that make up organic life.

14. Chromosomes LO 7.3 Chromosomes, genes and DNA and multiple births • Rod-shaped structures found in the nucleus of each cell • Are tightly wound strands of genes • Egg and sperm carry 23 chromosomes each • Missing or extra chromosome can cause mild to severe problems in development

15. Down syndrome is a form of developmental delay caused by an extra chromosome 21.

16. Chromosome Disorders LO 7.3 Chromosomes, genes and DNA and multiple births • Down Syndrome • Extra chromosome in twenty-first pair • Symptoms include almond-shaped, wide-set eyes, intellectual disability

17. Chromosome Disorders LO 7.3 Chromosomes, genes and DNA and multiple births • Klinefelter’s Syndrome • Extra sex chromosome in the twenty-third pair • XXY • Extra X produces male with reduced masculine characteristics, enlarged breasts, obesity

18. Chromosome Disorders LO 7.3 Chromosomes, genes and DNA and multiple births • Turner’s Syndrome • Twenty-third pair is missing an X • Very short, infertile, and sexually underdeveloped

19. Figure 7.2 Dominant and Recessive Genes and PKUThis figure shows the variation of parents carrying one or two recessive genes and the result of this in their offspring. (a) If only one parent carries the PKU gene, their children might be carriers, but will not have PKU.

20. Figure 7.2 (continued) Dominant and Recessive Genes and PKUThis figure shows the variation of parents carrying one or two recessive genes and the result of this in their offspring. (b) Only if both parents are carriers of PKU will a child have the 1 in 4 possibility of having PKU.

21. Prenatal Development LO 7.3 Chromosomes, genes and DNA and multiple births • Ovum • Female sex cell or egg • Fertilization • Union of the ovum and sperm

22. Prenatal Development LO 7.3 Chromosomes, genes and DNA and multiple births • Zygote • Cell resulting from the uniting of ovum and sperm • Mitosis • Separation of chromosomes, DNA duplication

23. Conception and Twins LO 7.3 Chromosomes, genes and DNA and multiple births • Monozygotic twins • Identical twins • Zygote splits into two separate masses of cells • Each cell develops into separate embryo

24. Conception and Twins LO 7.3 Chromosomes, genes and DNA and multiple births • Dizygotic twins • Fraternal twins • Two eggs fertilized by two different sperm • Two zygotes in the uterus at the same time

25. Figure 7.3 Monozygotic and Dizygotic TwinsBecause identical twins come from one fertilized egg (zygote), they are called monozygotic. Fraternal twins, who come from two different fertilized eggs, are called dizygotic.

26. Abby and Brittany Hensel LO 7.3 Chromosomes, genes and DNA and multiple births • Conjoined twins • Each have own heart, stomach and pair of lungs • Each controls one arm and one leg on one side of the body • Every action they undertake is a miracle of coordination

27. Abby and Brittany Hensel are conjoined twins who share one body from the waist down but are two distinctly different individuals.

28. Periods of Pregnancy LO 7.4 Germinal, embryonic, and fetal periods of pregnancy • Germinal period • First two weeks after fertilization • Zygote implants in the lining of the uterus • Stem cells • Stay in immature state until needed to produce more cells

29. The three periods of pregnancy are the germinal period, lasting about two weeks, the embryonic period, from about two to eight weeks, and fetal period, which lasts from eight weeks until the end of pregnancy.

30. Periods of Pregnancy LO 7.4 Germinal, embryonic, and fetal periods of pregnancy • Embryonic period • Two to eight weeks after fertilization • Major organs and structures of organism develop • Critical periods • Environmental influences can impact development • Teratogen • Any factor that can cause a birth defect

31. Periods of Pregnancy LO 7.4 Germinal, embryonic, and fetal periods of pregnancy • Embryonic period • Physical / structural problems can occur with the central nervous system, eyes, teeth and roof of the mouth

32. The three periods of pregnancy are the germinal period, lasting about two weeks, the embryonic period, from about two to eight weeks, and fetal period, which lasts from eight weeks until the end of pregnancy.

33. Table 7.2 Common Teratogens

34. Periods of Pregnancy LO 7.4 Germinal, embryonic, and fetal periods of pregnancy • Fetal period • Eight weeks after conception until the birth of the child • Organs continue to develop and become functional • Baby is born after 38 weeks

35. The three periods of pregnancy are the germinal period, lasting about two weeks, the embryonic period, from about two to eight weeks, and fetal period, which lasts from eight weeks until the end of pregnancy.

36. Miscarriage LO 7.4 Germinal, embryonic, and fetal periods of pregnancy • Usually occurs in the first three months • Organs are forming, becoming functional • 15 to 20 percent of all pregnancies end in miscarriage • Most likely caused by a genetic defect

37. This pregnant woman is getting a sonogram. Sonograms allow doctors to see any physical deformities and make accurate measurements of gestational age without risk to the mother or the fetus.

38. Physical Development in Infancy and Childhood LO 7.5 Physical changes in infancy and childhood • Reflexes • Innate (existing from birth) involuntary behavior patterns • Include sucking, rooting, Moro (startle), grasping, Babinski. • Taste and touch are well developed at birth

39. Physical Development in Infancy and Childhood LO 7.5 Physical changes in infancy and childhood • Vision • Rods are fairly well developed at birth • Cones take another six months • Gross and fine motor skills develop at a fast pace during infancy and early childhood • By age one, infant has tripled in weight

40. Figure 7.4 Five Infant ReflexesShown here are (a) grasping reflex; (b) startle reflex (also known as the Moro reflex); (c) rooting reflex (when you touch a baby's cheek it will turn toward your hand, open its mouth, and search for the nipple);

41. Figure 7.4 (continued) Five Infant Reflexes(d) stepping reflex; and (e) sucking reflex. These infant reflexes can be used to check the health of an infant's nervous system. If a reflex is absent or abnormal, it may indicate brain damage or some other neurological problem.

42. Figure 7.5 Six Motor MilestonesShown here are (a) raising head and chest—2 to 4 months, (b) rolling over—2 to 5 months, (c) sitting up with support—4 to 6 months.

43. Figure 7.5 (continued) Six Motor MilestonesShown here are (d) sitting up without support—6 to 7 months, (e) crawling—7 to 8 months, and (f) walking—8 to 18 months. The motor milestones develop as the infant gains greater voluntary control over the muscles in its body, typically from the top of the body downward. This pattern is seen in the early control of the neck muscles and the much later development of control of the legs and feet.

44. Cognitive Development LO 7.6 Looking at cognitive development and how language develops • Development of thinking, problem- solving, and memory • Scheme • Mental concept formed through experiences with objects and events

45. Piaget’s Stage Theory LO 7.6 Looking at cognitive development and how language develops • Children process new experiences through two processes • Assimilation • Children first try to understand new things in terms of schemes they already possess • Accommodation • Altering or adjusting old schemes to fit new information and experiences

46. Piaget’s Stage Theory LO 7.6 Looking at cognitive development and how language develops • Sensorimotor stage • Piaget’s first stage of cognitive development • Infant uses senses and motor abilities to interact with objects in the environment • Object permanence • The knowledge that an object exists even when it is not in sight

47. Piaget’s Stage Theory LO 7.6 Looking at cognitive development and how language develops • Preoperational stage • Second stage of cognitive development • Child uses language as a means of exploring the world • Egocentrism • Inability to see the world through anyone else’s eyes

48. Piaget’s Stage Theory LO 7.6 Looking at cognitive development and how language develops • Preoperational stage • Child uses language as a means of exploring the world • Centration • Child to focus only on one feature of object • Ignores other features • Conservation • Changing the appearance of an object does not change the object’s nature

49. Piaget’s Stage Theory LO 7.6 Looking at cognitive development and how language develops • Preoperational stage • Child uses language as a means of exploring the world • Irreversibility • Inability to mentally reverse an action

50. Figure 7.6 Conservation ExperimentA typical conservation task consists of pouring equal amounts of water into two glasses of the same size and shape. When the water from one of these glasses is poured into a taller, narrower glass, children who cannot yet conserve tend to focus (centrate) on the height of the water in the second glass, assuming that the second glass now has more water than the first one. In the second example, pennies are laid out in two equal lines. When the pennies in the top line are spaced out, the child who cannot yet conserve will centrate on the top line and assume that there are actually more pennies in that line.