Nature vs. Nurture: Influences on Human Development

1. Myers’ PSYCHOLOGY (7th Ed) Chapter 4 The Developing Person Cerepak Adapted from: James A. McCubbin, PhD Clemson University Worth Publishers

2. Nature and Nurture in Development • Development is influenced by both heredity and the environment • Each individual inherits a specific pattern of genes from his or her parents • However, the environment in which the individual grows affects the expression of those genes

3. Examples of Environment Affecting Genes • Maternal stress may alter the genetic material of her fetus. • An individual may have a genetic risk for Alzheimer’s but never develop the disorder due to being intellectually or physically active. Genes are inherited from parents

4. Continuity and Change in Development • For the ease of studying development, we speak of stages from infancy through old age; however, people develop in continuous fashion throughout life. • Even in stages marked by specific biological changes, the change occurs gradually

5. Definitions of basic terms • Life Span: the biological limits to life’s length , determined by specific hereditary factors • Life expectancy: the average length of time that a given age-based cohort is expected to live • Life course: the term used by sociologists to refer to the normal , expected set of events that take place over an individual’s life determined by society’s norms

6. Problems with Research Involving Aging • All research is quasi-experimental because if age and gender are the independent variables, they cannot be randomly assigned as treatment variables • However, experimental manipulations can be performed to test whether certain conditions have differential impact on different age groups.

7. Example: children in the 5-7 age group benefit more from auditory instructions than 9-11 age group

8. Another Problem with Research on Aging • As age groups get older, the samples become increasingly less representative. • 80 year olds are a select group of individuals compared to everyone born that year

9. Selection bias can operate in samples of adults as young as 25. • It may appear that high-risk/impulsive behaviors decrease with age, in reality, people who exhibit high-risk behaviors may have died.

10. Three Main Research Concepts • Age: the chronological age of the individual • Cohort: the historical period in which the individual was born • Time of Measurement: the historical period in which testing takes place • What factors are specific to your cohort? • What factors might be specific to the current period of time?

11. Types of Descriptive Research Designs • Cross-Sectional: Individuals from different cohorts are compared at one point in time. • Longitudinal: Individuals from one cohort are followed over several time periods. • Time-Lag: Individuals of the same age who were born at different times and are being tested in the same year are compared. Ex: comparing different generations of high school students on the same measure (SAT scores) to point out generational differences.

12. Sequential Research Designs • Research that attempts to replicate the findings of one longitudinal study by repeating it on another cohort. • Used to study the effect of time (not a time period!) • Seattle Longitudinal Study of adult intelligence found different patterns of changes in intelligence in different cohorts which changed their results.

13. Twin Studies- Not as perfect as we thought? • Twin studies were thought to provide clear-cut evidence on the nature-nurture issue but now that is being questioned: • Most identical twins actually had different prenatal environments which could have affected their growth differently-only 1% actually share a placenta, others have their own • Monozygotic and Dizygotic are usually compared because they are thought to share identical environments which is not true. • Studies on identical twins reared apart usually exaggerate the similarities and understate the differences.

14. Twins Reared Apart • Twins Reared Apart clip • How could you explain these similarities without using genes? • Anecdotal accounts v. scientific evidence

15. Prenatal Development and the Newborn • Developmental Psychology • a branch of psychology that studies physical, cognitive and social change throughout the life span

16. Prenatal Development and the Newborn

17. Prenatal Development(Prenatal means before birth) • Zygote - the newly fertilized egg • Not one in two makes it past the first 14 days. The zygote enters a 2 week period of rapid cell division. One cell becomes two, then four, then eight, etc. • After a week or dividing 7 times, the cells start to differentiate or specialize in function. Our genes direct this process. • At the end of the tenth day, the outer wall of the zygote attaches to the mother’s uterine wall and forms the placenta.

18. Pre-natal Development The placenta passes oxygen & nutrients to the fetus, as well as screens out teratogens. Embryo –The developing human organism from about 2 weeks after fertilization through the end of the eighth week. Fetus – The developing human organism from nine weeks after conception until birth.

19. Prenatal Development 40 days 45 days 2 months 4 months

20. Prenatal Development Teratogens Harmful agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm Examples: radiation, German measles, prescription and over the counter medicines, nicotine. Alcohol, drugs, viruses associated with STD’s. (lead to blindness & mental retardation)

21. FETAL ALCOHOL SYNDROME A series of physical & cognitive abnormalities that appear in children whose mothers consumed alcohol while pregnant. Symptoms may included noticeable facial disproportions.

22. REFLEXES AND PREFERENCES Within the first 30 minutes of birth, infants will turn their heads to watch a picture or look at a human face, or towards human voices. Prefer salty & sweet tastes. It knows the sound and smell of its mother. Newborns are born with reflexes: automatic, unlearned responses to a stimulus. a. Rooting reflex –when touched on the cheek, to open the mouth & search for the nipple. b. Sucking –when an object is placed in a baby’s mouth, he will suck on it.

23. Sucking Reflex • https://www.youtube.com/watch?v=vCOhBmC6uvo

24. REFLEXES c. Grasping reflex – if an object is placed into a baby’s palm. The baby will to grasp the object. d. Moro reflex-when startled a baby will fling his arms out quickly & retract them, making himself as small as possible. https://www.youtube.com/watch?v=PTz-iVI2mf4 e. Babinski reflex – when a baby’s foot is stroked, he will spread his toes.

25. The Grasping Reflex

26. DEVELOPMENT Infancy is the first year of a child’s life. From ages one to three, a child is called a toddler. Childhood is the ages of 3 until 13. Adolescence is from puberty until adulthood.

27. PHYSICAL DEVELOPMENT During prenatal development, your body makes nerve cells at the rate of 4000 per second. However, your nerve system was still very immature. You could not walk, talk or have memory, because your brain had not yet created neural networks that would let you perform these behaviors.

28. The Newborn • Habituation • decreasing responsiveness with repeated stimulation

29. The Newborn Having habituated to the old stimulus, newborns preferred gazing at a new one

30. At birth 3 months 15 months Cortical Neurons Infancy and Childhood: Physical Development • Maturation • biological growth processes that enable orderly changes in behavior • relatively uninfluenced by experience • The development of neural pathways is illustrated on the right.

31. Most of us can not remember anything before the age of 3 or even the age of 5 because we did not have the neural connections in our brains that allow us to remember. • We also didn’t have the language usually associated with explicit memories making the memories we might have diffecult to communicate.

32. PHYSICAL DEVELOPMENT OF INFANTS Newborn babies can suck, turn their heads, look at things, cry, smile, show signs of fright or surprise.  At the age of : 1-month  -babies can pull up their chin 2 months –babies can pull up their chest 3 months  - babies lift their heads & reach 4 months  - smile & sit with support 5-6 months  – grasp at objects/roll over 7 months    - sit alone 8-9 months –  stand 10 months – crawl 12 months – pull self into a standing position/begin to walk 13 months  - climb stair steps 14 months – stand-alone 15 months  -walk alone

33. Jean Piaget-1896-1980

34. Jean Piaget • A pioneer in the study of developmental psychology who introduced a stage theory of cognitive development that lead to a better understanding of children’s thought processes. • Piaget’s greatest contribution was to point out that the way children think differs from the way adults think.

35. Infancy and Childhood: Cognitive Development • Schema • a concept or framework that organizes and interprets information • Cognition • All the mental activities associated with thinking, knowing, remembering, and communicating

36. Infancy and Childhood: Cognitive Development • 1. Assimilation • interpreting one’s new information in terms of one’s existing schemas • Information about a new object is fitted into an existing schema. Example: A child is given a vitamin pill for the first time and calls it candy. The child does not have a schema for a vitamin pill, but does have one for candy.

37. 2. Accommodation • adapting one’s current understandings (schemas) to incorporate new information • Information about the new object forces a change or modification of the existing schema. Example: The child realizes that the vitamin comes once a day and is not a reward for good behavior. Attempts at chewing it have revealed that it does not taste like candy. The child then develops a new schema for vitamins.

38. Typical Age Range Description of Stage Developmental Phenomena Birth to nearly 2 years Sensorimotor Experiencing the world through senses and actions (looking, touching, mouthing) • Object permanence • Stranger anxiety About 2 to 6 years Preoperational Representing things with words and images but lacking logical reasoning • Pretend play • Egocentrism • Language development About 7 to 11 years Concrete operational Thinking logically about concrete events; grasping concrete analogies and performing arithmetical operations • Conservation • Mathematical transformations About 12 through adulthood Formal operational Abstract reasoning • Abstract logic • Potential for moral reasoning Piaget’s Stages of Cognitive Development

39. Mnemonics Video for Memorizing Piaget’s Stages • https://www.youtube.com/watch?v=OXd5nxrBVrs

40. Infancy and Childhood: Cognitive Development • Object Permanence • the awareness that things continue to exist even when not perceived

41. Infancy and Childhood: Cognitive Development • Conservation • the principle that properties such as mass, volume, and number remain the same despite changes in the forms of objects

42. Infancy and Childhood: Cognitive Development • Egocentrism • the inability of the preoperational child to take another’s point of view • Theory of Mind • people’s ideas about their own and others’ mental states- about their feelings, perceptions, and thoughts and the behavior these might predict • Autism • a disorder that appears in childhood • Marked by deficient communication, social interaction and understanding of others’ states of mind

43. Social Development • Stranger Anxiety • fear of strangers that infants commonly display • beginning by about 8 months of age • Attachment • an emotional tie with another person • shown in young children by their seeking closeness to the caregiver and displaying distress on separation

44. Attachment • Three elements contribute to the infant-parent bond that forms during attachment. • A) Body Contact • B) Familiarity -Critical Period -Imprinting • C) Responsiveness • -Attachment • -Parenting Patterns

45. Imprinting-Konrad Lorenz

46. Social Development • Harry Harlow’s (1906-1981) Surrogate Mother Experiments-1950’s • Monkeys preferred contact with the comfortable cloth mother, even while feeding from the nourishing wire mother

47. Social Development • Monkeys raised by artificial mothers were terror-stricken when placed in strange situations without their surrogate mothers.

48. Percentage of infants who cried when their mothers left 100 80 Day care 60 40 Home 20 0 3.5 5.5 7.5 9.5 11.5 13.5 20 29 Age in months Social Development • Groups of infants left by their mothers in a unfamiliar room (from Kagan, 1976).

49. Social Development • Basic Trust (Erik Erikson) • a sense that the world is predictable and trustworthy • said to be formed during infancy by appropriate experiences with responsive caregivers • Self-Concept • a sense of one’s identity and personal worth

50. Social Development: Child-Rearing Practices • Authoritarian • parents impose rules and expect obedience • “Don’t interrupt.” “Why? Because I said so.” • Permissive • submit to children’s desires, make few demands, use little punishment • Authoritative • both demanding and responsive • set rules, but explain reasons and encourage open discussion