1. Developmental Psychology Week 3: Physical Development

2. Outline Physical development and changes - infancy, toddler, childhood, adolescent, adult, old age Brain development and changes - infancy, toddler, childhood, adolescent, adult, old age Motor development and changes - infancy, toddler, childhood, adolescent, adult, old age 2

3. Stages 3

4. Growth trends in infancy and toddlerhood Newborns grow rapidly A child weighing 7.5 pounds at birth may weigh 20 to 25 pounds by 12 months At 18 months, a child is usually walking and beginning to talk Infancy ends at about 18 months, when children represent the world abstractly through language 4

5. Growth trends in infancy and toddlerhood Greatest physical growth during the first two years 5 Length at birth 12in Height at 1yr 32in Height at 2yr 36in Weight at birth 6lbs Weight at 5mth 15lbs Weight at 1yr 22lbs Weight at 2yr 30lbs Infant and toddlers grow in spurts Bodies transform into round, chubby babies in first year – baby fat

6. Concept in physical growth Cephalocaudal trend Growth from head to tail Change in body proportions 6 Head 1/5 of total Head ¼ of total Head most rapid growth

7. Concept in physical growth Proximodistal trend From near to far, growth from the centre of the body towards outwards Order of growth Head, chest and trunk Arms and legs Hands and feet 7

8. Maturation & Growth Skeletal Development The skeletal structures that form during the prenatal period are initially soft cartilage that will gradually harden into bony material Skull bones are separated by six soft spots, or fontanelles, that are gradually filled in by minerals to form a single skull by age 2 8

9. An Overview of Maturation & Growth Skeletal Development Skeletal age research has been used to determine that girls mature faster then boys At birth girls are only 4 to 6 weeks ahead of boys in skeletal maturity By age 12 the gender “maturation gap” has widened to 2 full years 9

10. An Overview of Maturation & Growth Muscular Development Neonates are born with all the muscle fibers they will ever have At birth, muscle tissue is 35% water, and it accounts for no more than 18 to 24% of a baby’s body weight Muscle fibers soon begin to grow as the cellular fluid in muscle tissue is bolstered by the addition of protein and salts Muscular development proceeds in cephalocaudal and proximodistal directions 10

11. An Overview of Maturation & Growth Muscular Development Maturation of muscles very gradually during childhood accelerated during early adolescence by mid twenties, skeletal muscle accounts for 40% of the body weight for a man and 24% of the body weight for a female 11

12. Body Growth in toddler years Changes in Body Size and Proportions 2 to 3 inches in height each year 4-6 pounds in weight each year. Child gradually becomes thinner Posture and balance improve Individual differences in body size are even more apparent. Child’s ethnic heritage must be considered. 12

14. Between ages 2 and 6, approximately 45 epiphyses emerge in various parts of the skeleton. X-rays permit doctors to estimate children’s skeletal age Children start to lose their primary teeth. Childhood tooth decay remains high 14

15. Activity How early, and to what extend, did you experience tooth decay in childhood? What factors might have been responsible?

16. Asynchronies in Physical Growth Physical growth is an asynchronous process. General growth curve for overall body size -- how does it change? (fast, slow, fast) Exceptions to this trend are found in the development of the reproductive and lymph systems. During the first few years, the brain grows faster than any other part of the body. 16

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18. Puberty: The Physical Transition from Child to Adult Growth Spurt in Adolescent Years Weight gain of 15 to 65 pounds Height gain of 4 to 12 inches The Adolescent Growth Spurt The rapid increase in physical growth marks the beginning of adolescence 18

19. Puberty: The Physical Transition from Child to Adult The Adolescent Growth Spurt Girls enter growth spurt by 10.5, reach peak growth by 12, return to a slower rate of growth by age 13 to 13.5 Boys lag behind girls by 2 to 3 years Begin growth spurt by 13, peak at 14, return to a more gradual rate of growth by age 16 Have two growth spurts In addition to growing taller and heavier, the body assumes an adult-like appearance during adolescence Widening of hips for girls Broadening of shoulders for boys 19

20. Puberty: The Physical Transition from Child to Adult Sexual Maturation Sexual Development in Girls Maturation begins about age 9 or 10 as fatty tissues accumulate about their nipples and pubic hair begins to appear a little later As a girl enters her height spurt, the breasts grow rapidly and the sex organs begin to mature At about age 12.5, the average girl in Western societies reaches menarche 20

21. Puberty: The Physical Transition from Child to Adult Sexual Maturation Sexual Development in Boys Sexual maturation begins at about age 11 or 12 with an enlargement of the testes, which is accompanied with unpigmented pubic hair By the time the penis is fully developed at age 14.5 to 15, most boys will have reached puberty and are now capable of fathering a child Later boys begin to sprout facial hair and their voice lowers 21

22. The Psychological Impacts of Puberty General Reactions to Physical Changes Girls typically become quite concerned about their appearance and worry about how other people will respond to them Few girls today are traumatized by menarche, but at the same time, few are overjoyed about becoming a woman Boys’ body images are more positive than those of girls, and they are much more likely than girls to welcome their weight gains Teenage boys hope to be tall, hairy, and handsome, and may become preoccupied with the aspects of body image that center on physical and athletic prowess 22

23. The Psychological Impacts of Puberty Social Impacts of Pubertal Changes Rites of Passage Many societies (non-industrialized) view pubertal changes as a sign and rituals are conducted that the child is becoming an adult In some other societies, the mark of puberty causes conflicts amongst child and parent 23

24. The Psychological Impacts of Puberty Does Timing of Puberty Matter? Puberty does have some meaningful implications, although its impact differs somewhat for boys and girls Possible impacts on boys Research suggests that boys who mature early enjoy a number of social advantages over boys who mature late Possible impacts on girls Maturing early may be somewhat of a disadvantage Findings suggest that early-maturing girls are somewhat less outgoing and less popular than their pre-pubertal classmates 24

25. The Psychological Impacts of Puberty Adolescent Sexuality Cultural Influences on Sexuality Societies clearly differ in the education they provide children about sexual matters and in their attempts to prepare them for their roles as mature sexual beings Sexual Attitudes and Behaviour Adolescents now firmly believe that premarital sex with affection is acceptable, although, like teens of earlier eras, they think that casual or exploitative sex is wrong Sexual attitudes today are highly variable and seem to reflect an increased confusion about sexual norms 25

26. The Psychological Impacts of Puberty Personal and Social Consequences of Adolescent Sexual Activity Changes in hormones during puberty cause an increase in sex drive (libido) and the responsibility of managing your sexuality Sexually Transmitted Disease In the U.S., one in five sexually active adolescents contracts a sexually transmitted disease (STD) Teenage Pregnancy and Childbearing Each year in the U.S., more than one million unmarried teenage girls become pregnant The consequences are likely to include an interrupted education, loss of contact with her social network, and if she is one of the 50% who drop out of school, a future of low-paying jobs that perpetuates her economic disadvantage 26

27. Causes and Correlates of Physical Development Biological Mechanisms Effects of Individual Genotypes Unique combination of genes influence our physical growth and development Hormonal Influences- The Endocrinology of Growth By the fourth prenatal month, the thyroid gland has formed and begins to produce thyroxine The most critical of the endocrine glands is the pituitary, a “master gland”, located at the base of the brain that triggers the release of hormones from all other endocrine glands The pituitary produces a growth hormone that stimulates the rapid growth and development of body cells 27

28. Causes and Correlates of Physical Development Environmental Influences Nutrition Diet is perhaps the most potent environmental influence on human growth and development Adequate nutrition, in the form of total calories, protein, and vitamins and minerals is necessary for children to reach their growth potentials The three growth-retarding diseases that stem from under nutrition are: Marasmus, Kwashiorkor, and Iron Deficiency Anemia 28

29. Growth retarding diseases Marasmus is one component of protein-energy malnutrition (PEM) is a severe form of malnutrition caused by inadequate intake of protein and calories, usually occurs in the first year of life, resulting in wasting and growth retardation. Kwashiorkor, literally "the disease of the displaced child" in the language of Ga, was first defined in the 1930s in Ghana. Kwashiorkor is one of the more severe forms of protein malnutrition and is caused by inadequate protein intake. Iron deficiency anaemia not only impairs the production of red cells in the blood, but also affects general cell growth and proliferation in tissues like the nervous system and the gastrointestinal tract. 29 Up to 50% of population can suffer from anaemia

30. Causes and Correlates of Physical Development Environmental Influences Nutrition The most immediate effect of over nutrition is that children may become obese and face added risk of diabetes, high blood pressure, and heart, liver, and kidney disease 30

31. Group Discussion What is your attitude toward breastfeeding? Is it influenced by your cultural background? Explain.

32. Causes and Correlates of Physical Development Emotional Stress and Lack of Affection Nonorganic Failure to Thrive An infant growth disorder, caused by lack of attention and affection, that causes growth to slow dramatically and stop Deprivation Dwarfism A childhood growth disorder that is triggered by emotional deprivation and characterized by decreased production of growth hormone (GH), slow growth, and small stature 32

33. Variations in physical development Individual Variations Not only is the development of body systems an uneven process, but there are sizable individual variations in the rates at which individuals grow Cultural Variations There are meaningful cultural and sub-cultural variations in physical growth and development People from Asia, South America, and Africa tend to be smaller than North Americans, northern Europeans, and Australians Asian American and African American children tend to mature faster than European American and European children 33

34. Influencing factors on growth and health Heredity and Hormones Children’s physical size and rate of growth are related to that of their parents Genes – by control of the pituitary gland and hormone secretion Growth hormone (GH) – all body tissue except for CNS and genitals Thyroid secreting hormone (TSH) – brain development 34

35. Influencing factors on growth: Emotional well being Stress can affect negatively – more prone to intestinal and respiratory illnesses Emotional deprivation -> Psychosocial dwarfism 35 Girl, 15yrs, deprived had small stature, similar to an average 10yr old. At 16.5 and at 17 grew at a slightly more rapid rate

36. Influencing factors on growth:Nutrition Growth depends on proper nutrition Psychology of eating – develop preference for similar foods to what person they admire eats Proper diet should be well balanced, wholesome food – protein, vitamins, minerals, iron, calcium 36

37. FACTORS AFFECTING GROWTH AND HEALTH Nutrition Preschoolers’ appetites decrease because growth has slowed. Picky eaters. Need high-quality diet. The social environment and emotional climate at mealtimes have a powerful impact on children’s eating habits. 37

38. Nutrition (continued) Repeated exposure to a new food also increases children’s acceptance. Insufficient amounts of iron, calcium, vitamin C, and vitamin A are the most common diet deficiencies of the preschool years. By age 7, low-SES children in the United States are, on the average, about 1 inch shorter than their middle-class counterparts. 38

39. Influencing factors on growth:Infectious diseases Malnutrition spiral Common in developing nations Infectious Disease Growth, health Malnutrition 39

40. FACTORS AFFECTING GROWTH AND HEALTH Infectious Disease and Malnutrition Ordinary childhood illnesses have no effect on physical growth. In developing nations, many children do not receive a program of immunizations. Disease is a major cause of malnutrition, and, through it, affects physical growth. Most growth retardation and deaths due to diarrhea in developing countries can be prevented with oral rehydration therapy (ORT) 40

41. FACTORS AFFECTING GROWTH AND HEALTH Immunization Of American preschoolers, 24% lack essential immunizations Poverty stricken families, 40% percent of the children lack immunization Misconceptions about vaccinations also contribute to inadequate immunization rates. Not as bad issue in Singapore, however, low income families may overlook this 41

43. Irritable temperament of child

44. SES – poverty, low education families

45. Lacking adequate childcare42

46. Factors Related to Childhood Injuries Injuries take place within a complex ecological system. Boys are more likely to be injury victims than girls. Irritability, inattentiveness, and negative mood are also related to childhood injuries. Poverty, low parental education, and more children in the home are strongly associated with injury. United States ranks among the highest in childhood injury mortality 43

47. FACTORS AFFECTING GROWTH AND HEALTH Childhood Injuries Auto accidents, drowning, and burns are the most common injuries during early childhood. Motor vehicle collisions are the leading cause of death among children over 1 year of age. 44

48. FACTORS AFFECTING GROWTH AND HEALTH Sleep Total sleep declines from 12 /13 hours (age 2-3yrs) to 10 / 11 hours (age 4-6yrs) Bedtime rituals are common Nightmare declines between ages 3 to 6. About 20% to 25% of preschoolers experience difficulty falling and staying asleep. 45

49. Physical Growth in Adulthood Less dramatic changes Perceptual abilities tend to decline in mid adulthood e.g. presbyopia, glaucoma, presbycusis Muscle-fat makeup = middle age spread Bone density reduces, threat of osteoporosis Decline in fertility (climacteric), menopause, andropause 46

50. Physical growth in late adulthood Women’s life expectancy is longer than men’s by 4 – 7 years Differential neuronal loss occurs thus affecting functioning More men than women are hearing impaired while it is the other way for visual impairments Sleep apnea becomes more common as one ages 47

51. Continuing Assessment (CA1), Mid Semester Test (30%) Details To demonstrate an understanding of lifespan development perspectives and to be able to apply that knowledge to a specific individual’s circumstances both in written essays and group debates.

52. Topics: Choose one of the following topics and write an essay. Debates on the developmental issues will be scheduled in tutorials to help you prepare for the essays. 1- Explain how do genetic and environmental factor work together to promote a child’s temperament? Cite examples from research. 2- Adolescent idealism and criticism, although troublesome for parents, are beneficial in the long run to both the developing individual and society. Explain why this is so. 3- Describe gender differences in traits usually desired in a long-term partner. What findings indicate that both biological and social forces contribute to those differences? 4- Discuss age-related changes in conceptions of and attitudes toward death, and cite factors that influence death anxiety.

53. Details and Deadline Life Course Essay: 1500 Word (Double spacing & size 12 fonts, Times New Romans) Submissions & Deadline: 7pm 1 March 2011