Chapter 4
Physical Development in Infancy
CHAPTER OUTLINE
Growth and Stability
♦ Physical Growth: The Rapid Advances of Infancy
♦ The Nervous System and Brain: The Foundations of Development
♦ Integrating the Bodil
...
Chapter 4
Physical Development in Infancy
CHAPTER OUTLINE
Growth and Stability
♦ Physical Growth: The Rapid Advances of Infancy
♦ The Nervous System and Brain: The Foundations of Development
♦ Integrating the Bodily Systems: The Life Cycles of Infancy
♦ SIDS: The Unanticipated Killer
Motor Development
♦ Reflexes: Our Inborn Physical Skills
♦ Motor Development in Infancy: Landmarks of Physical Achievement
♦ Nutrition in Infancy: Fueling Motor Development
♦ Breast or Bottle?
♦ Introducing Solid Foods: When and What?
The Development of the Senses
♦ Visual Perception: Seeing the World
♦ Auditory Perception: The World of Sound
♦ Smell and Taste
♦ Sensitivity to Pain and Touch
♦ Multimodal Perception: Combining Individual Sensory Inputs
LEARNING OBJECTIVES
After you have read and studied this chapter, you should be able to answer the following questions.
1. How do the human body and nervous system develop?
2. Does the environment affect the pattern of development?
3. What developmental tasks must infants accomplish in this period?
4. What is the role of nutrition in physical development?
5. What sensory capabilities do infants possess?51
PRACTICE TEST – PRETEST
Circle the correct answer for each of the following multiple choice questions and check your answers with the
Answer Key at the end of this chapter.
1. What principle states that simple skills develop independently and are later integrated into more complex skills?
a. proximocaudal c. continuity
b. hierarchical integration d. cephalocaudal
2. Frank is 6 months old and can reach out and grab a toy with his hand, but he will not be able to pick up a small
toy with his finger and thumb until he is 9 months old. This illustrates what developmental principle?
a. cephalocaudal principle
b. proximodistal principle
c. principle of hierarchical integration
d. principle of the independence of systems
3. An infant received brain damage as the result of an accident, but through various experiences the brain was able
to develop to overcome most of the problems. This ability of the brain is called
a. plasticity. c. sensitivity.
b. kwashiorkor. d. integrity.
4. The rate of SIDS in the United States has been declining partially due to the
a. respiratory occlusion reflex.
b. reflexes present at birth.
c. back-to-sleep guideline.
d. understanding sensitive periods for the formation of sleep habits.
5. Newborns do not sleep the same amount as their parents. Approximately how long do newborns sleep each day?
a. 10 hours c. 14 hours
b. 12 hours d. 16 hours
6. What is the incidence of sudden infant death syndrome?
a. 1 in 300 c. 1 in 1000
b. 2 in 100 d. 2 in 1000
7. Newborns react to loud noises automatically. This reaction is called the
a. Babinski reflex. c. rooting reflex.
b. Moro reflex. d. startle reflex.
8. Zelazo and his colleagues conducted a study in which they provided 2-week-old infants practice in walking for
four sessions of 3 minutes each over a 6-week period. The results showed that the children who had the walking
practice actually began to walk unaided several months earlier than those who had had no such practice. What
did the researchers conclude?
a. Exercise of the stepping reflex was performed qualitatively better in practiced infants than in unpracticed
infants.
b. Exercise of the stepping reflex helps the brain's cortex to develop the ability to walk.
c. Early gains in stepping reflex are associated with proficiency in motor skills in adulthood.
d. Parents should make extraordinary efforts to stimulate their infant's reflexes.
9. When does crawling typically appear?
a. 3-5 months c. 8-10 months
b. 6-8 months d. 10-12 months52
10. At what age can you expect a child to walk by herself?
a. 8 months c. 12 months
b. 10 months d. 15 months
11. On television you see a child from a poor country whose growth has stopped. This child is suffering from
malnutrition and has a disease called
a. anemia. c. kwashiorkor.
b. marasmus. d. acetycholine deficiency.
12. What is the best form of nourishment for infants under the age of one?
a. bottle formula c. cereals
b. breast milk d. All of the answers are correct.
13. By the age of 5 months, the average infant’s birth weight has _____ to around _____ pounds.
a. doubled; 22 c. doubled; 15
b. tripled; 15 d. tripled; 22
14. The gap between neurons through which they communicate with each other is the
a. synapse. c. dendrite.
b. myelin. d. axon.
15. What specific skill permits infants to pinpoint the direction from which a sound is emanating?
a. sensation c. sound habituation
b. perception d. sound localization
16. Which of the following reflexes is permanent?
a. rooting c. stepping
b. sucking d. swimming
17. In the United States the poverty rate for children under the age of 3 has
a. decreased. c. stabilized.
b. remained the same. d. increased.
18. Joan’s baby has stopped growing due to a lack of stimulation and attention. Her baby is suffering from
a. marasmus. c. nonorganic failure to thrive.
b. kwashiorkor. d. SIDS.
19. Who developed the visual cliff?
a. Gibson c. Fantz
b. Pavlov d. Skinner
20. Which of the following is an example of a gross motor skill?
a. rolling over c. coping circles
b. placing a peg in a board d. pincer grasp
KEY NAMES
Match the following names with the most accurate description and check your answers with the Answer Key
at the end of this chapter.
1. ___ Esther Thelen a. “blooming, buzzing confusion”
2. ___ Robert Fantz b. Dynamic systems theory
3. ___ Eleanor Gibson c. SID S53
4. ___ William James d. visual preferences
5. ___ Lewis Lipsitt e. visual cliff
KEY VOCABULARY TERMS
Explain the difference between the following pairs of terms.
1. Cephalocaudal principle; Proximodistal principle
2. Principle of hierarchical integration; Principle of the independence of systems
3. Marasmus; Kwashiorkor
4. Sensation; Perception
How are the following terms related?
5. Neuron, Myelin, Synapse
Fill in the blanks next to each definition with the appropriate term. The first letter of each term from top to
bottom will spell out the term for the final definition. (NOTE: Some terms may be from previous chapters.)
6. _ _ _ _ _ _ _ _ _ _ The degree to which a developing structure or behavior is modifiable due to
experience.
_ _ _ Freud’s term for the rational part of the personality.
_ _ _ _ _ _ _ _ Unlearned, organized, involuntary responses that occur automatically in the
presence of certain stimuli.
_ _ _ _ _ _ _ _ The upper layer of the brain is the _____ cortex.
_ _ _ _ _ _ _ _ _ _ An incision made to increase the vaginal opening to allow the baby to pass
during birth.
_ _ _ _ _ _ _ _ _ _ _ _ _ Growth from the center of the body outward.
_ _ _ _ _ _ In nonorganic failure to _____, infants stop growing due to a lack of
stimulation and attention.
_ _ _ _ _ _ SIDS or sudden ____ death syndrome occurs in the first year of life.
_ _ _ _ _ _ _ A form of conditioning in which a response is strengthened or weakened
depending on its consequences.
_ _ _ _ _ The average performance of a large sample of children of a given age.
The sorting out, interpretation, analysis, and integration of stimuli involving the sense organs and brain is
_ _ _ _ _ _ _ _ _ _.
Look up the definitions of each of the following terms and write a specific example of each.
7. SIDS 12. Sensitive period
8. Rhythms 13. Rapid eye movement (REM)
9. Infant states 14. Brazelton Neonatal Behavioral Scale54
10. Multimodal approach to perception 15. Nonorganic failure to thrive
11. Affordances 16. Dynamic system theory
PROGRAMMED REVIEW
Fill in the blanks in the following programmed review and check your answers with the Answer Key at the
end of this chapter.
Growth and Stability
1. The average newborn weighs just over ______ pounds and its length is ______ inches.
Physical Growth: The Rapid Advances of Infancy
2. Over the first two years of a human’s life, growth occurs at a ______ pace. By the age of 5 months, the
average infant’s birthweight has ______, and by the first birthday, weight has ______. By the end of its
second year, the average child weighs ______ times its birthweight. Of course there is a good deal of variation
among infants.
3. By the end of the first year, the typical baby is ______ inches tall, and by its second birthday, the child usually
has attained a height of _____ feet.
4. There are gender and ethnic differences in weight and length. Girls are slightly ____ and weigh slightly ____
than boys; furthermore, Asian infants tend to be slightly _____ than North American Caucasian infants, and
African American infants tend to be slightly ______ than North American Caucasian infants.
5. Four major principles govern infant growth. According to the ______ principle, growth follows a pattern that
begins with the head and upper body parts and then proceeds to the rest of the body. According to the ______
principle, development proceeds from the center of the body outward. The principle of ______ integration
states that simple skills typically develop separately and independently. The principle of ______ of systems
suggests that different body systems grow at different rates.
The Nervous System and Brain: The Foundations of Development
6. The nervous system comprises the ______ and the ______ that extend throughout the body. Like all cells,
neurons have a cell body containing a ______. They communicate using ______ to receive messages and an
_____ to carry messages. Neurons communicate by means of _____ that travel across small gaps, know as
_____, between neurons.
7. Infants are born with between _____ billion neurons. Unused neurons are eliminated in a process called
synaptic _____. The result of this process allows established neurons to build more elaborate _____ networks
with other neurons.
8. After birth, neurons continue to ______ in size and become coated with ______, the fatty substance that helps
insulate them and speeds the transmission of nerve impulses. The brain ______ its weight in the first two years
and reaches more than ______ of adult weight and size by the age of two.
9. Neurons become arranged by ______. Some move into the ______ cortex, the upper layer of the brain, and
others move to ______ levels.
10. Synapses and myelinization experience a growth spurt at around ___ to ____ months in the areas of the cortex
involving auditory and visual skills (areas called the _____ cortex and the ______ cortex).55
11. _____ ________ Syndrome, a devastating injury that comes from a form of child abuse in which an infant is
shaken by a caretaker, can lead the ____ to rotate within the skull, causing _____ vessels to tear and destroying
the intricate connections between neurons.
12. The brain’s _____, or degree to which a developing structure or behavior is modifiable due to experience, is
relatively great for the brain. A ______ period is a specific but limited time during which the organism is
particularly susceptible to environmental influences.
Integrating the Bodily Systems: The Life Cycles of Infancy
13. One of the most important ways that behavior becomes integrated is through the development of various body
______, repetitive cyclical patterns of behavior. An infant’s ______ is the degree of awareness it displays to
both internal and external stimulation.
14. Some of the different states that infants experience produce changes in ______ activity in the brain reflected in
different patterns of brain ______ which can be measured by an ______.
15. On average, newborn infants sleep ______ hours a day. They experience a period of active sleep similar
though not identical to ______ eye movement or REM sleep found in older children and adults. REM sleep
provides a means for the brain to stimulate itself, a process called ______.
SIDS: The Unanticipated Killer
16. When seemingly healthy infants die in their sleep, it is probably due to ______ infant death syndrome (SIDS).
The number of SIDS deaths has decreased since the American Academy of Pediatrics suggests the _____
guideline that babies sleep on their back. SIDS is the leading cause of death in children under the age of
_____. Lipsitt believes that SIDS hinges on infant reflexes, specially the _____ occlusion reflex.
Motor Development
Reflexes: Our Inborn Physical Skills
17. Reflexes are _____, organized involuntary responses that occur automatically in the presence of certain
stimuli. The ______ reflex makes a baby who is lying face down in a body of water paddle and kick. The
______ reflex seems designed to protect the eye from too much direct light. Researchers who focus on
evolutionary explanations of development attribute the gradual disappearance of reflexes to the increase in
______ control over behavior.
18. Reflexes are ______ determined and ______ throughout all infants. The _____ reflex is activated when
support for the neck and head is suddenly removed. There are some ______ variations in the ways they are
displayed however. Reflexes can serve as helpful ______ tools for pediatricians.
Motor Development in Infancy: Landmarks of Physical Achievement
19. By the age of _____ months, many infants become rather accomplished at moving themselves in particular
directions. Crawling appears typically between _____ months. At around the age of ______ months, most
infants are able to walk by supporting themselves on furniture. Babies are able to sit without support by the
age of ______ months.
20. By the age of ______ months, infants show some ability to coordinate the movements of their limbs. By the
age of _____ months, infants are able to pick small objects off the ground, and by the time they are _____ old,
they can drink from a cup. Infants first begin picking up things with their whole hand, but as they get older
they use a _____ grasp where the thumb and index finger meet to form a circle.
21. The _____ systems theory described how motor behaviors are assembled. This theory is noteworthy for its
emphasis on a child’s own _____.56
22. The timing of the milestones is based on ______, the average performance of a large sample of children at a
given age. One of the most widely used techniques to determine infants’ normative standing is the ______
Neonatal Behavior Assessment Scale, a measure designed to determine infants’ ______ and behavioral
responses to their environment.
23. Variations in the timing of motor skills seem to depend in part on parental ______ of what is the appropriate
schedule for the emergence of specific skills that is, by ______ factors. However, there are certain ______
determined constraints on how early a skill can emerge.
Nutrition in Infancy: Fueling Motor Development
24. The rapid physical growth that occurs during infancy is fueled by the ______ that infants receive. ______ is
the condition of having an improper amount and balance of nutrients. Children who have been chronically
malnourished during infancy later score lower on _____ tests and tend to do less well in ______. The problem
of malnutrition is greatest in ______ countries.
25. Some ______ children live in poverty in the United States and the poverty rate for children under the age of
_____ has increased. Although these children rarely become severely malnourished, they are susceptible to
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