Infancy Physical Development

Nutrition • Breast- vs Bottle-Feeding

– Today, nearly two-thirds of American mothers breast-feed their babies, although most do so for only a few months. Less than 40% in underdeveloped countries do.

– Breast-feeding offers many nutritional and health advantages over bottle-feeding.

– Breast-fed babies in impoverished regions of the world are less likely to be malnourished and more likely to survive the first year of life. Yet, many mothers in the developing world do not know about the benefits.

– Some mothers cannot nurse because of physiological or medical reasons.

– Breast milk is easily digestible and, as a result, breast-fed babies become hungry more often than bottle-fed infants, making breast-feeding inconvenient for many employed mothers.

– Preterm infants benefit from the antibodies and easy digestibility of breast milk.

– Breast- and bottle-fed youngsters in industrialized nations do not differ in psychological adjustment.

III. FACTORS AFFECTING EARLY PHYSICAL GROWTH• Heredity• Nutrition

– A baby’s energy needs are twice as great as those of an adult.

– Twenty-five percent of an infant’s caloric intake is devoted to growth. If a baby’s diet is deficient in either quantity or quality of nutrients, growth can be permanently stunted.

Nutrition

• A baby’s energy needs are twice as great as those of an adult.

• Babies as newborns become hungry every 1 ½ to 2 hours if breastfed and every 3 to 4 hours if bottle.

• Babies under 1 should not receive cows milk

• Twenty-five percent of an infant’s caloric intake is devoted to growth. If a baby’s diet is deficient in either quantity or quality of nutrients, growth can be permanently stunted.

• Breast feeding advised by AAP for first 6 months and include as part of diet until at least 1 year—Canada 2 years.

Nutrition cont.

• No bottle propping (ears and teeth) and warm or cold?• What about burping?• Are Chubby Babies at Risk for Later Overweight and

Obesity? – Only a slight correlation exists between fatness in infancy and

obesity at older ages.

– Infant and toddlers can eat nutritious foods freely, without risk of becoming too fat.

– Physical exercise also guards against excessive weight gain.• At six months introduce foods one at a time. Avoid cheese

and cow’s milk until one. Cereals usually first, not wheat.

Nutrition cont. • Malnutrition

– Recent evidence indicates that 40 to 60 percent of the world’s children do not get enough to eat.

– Marasmus is a wasted condition of the body usually appearing in the first year of life that is caused by a diet low in all essential nutrients.

– Kwashiorkor is a disease usually appearing between 1 and 3 years of age that is caused by a diet low in protein. Symptoms include an enlarged belly, swollen feet, hair loss, skin rash, and irritable, listless behavior.

– Children who survive these forms of malnutrition grow to be smaller in all body dimensions and their brains can be seriously affected.

– Iron-deficiency anemia, a condition common among poverty-stricken infants and children, interferes with many central nervous system processes.

– Early nutritional intervention is important, before the effects of early malnutrition are allowed to run their own course.

Figure 3.5

Physical Development in Infancy

Maturation

• Physical growth and development of the body, brain, and nervous system• Increased muscular control occurs in patterns• Cephalocaudal: From head to toe• Proximodistal: From center of the body to the extremities

Changes in Muscle-Fat Makeup• Body fat, which helps the

infant maintain a constant body temperature, increases after birth and peaks around 9 months of age.

• Toddlers become more slender, a trend that continues into middle childhood.

• Muscle tissue increases very slowly and does not peak until adolescence.

• Girls have a higher ratio of fat to muscle than boys.

Appearance of Teeth

• An infant’s first tooth usually appears between 4 to 6 months of age. By age 2, the average child has 20 teeth.

• A child who gets her teeth early is likely to be advanced in physical maturity.

• 65 percent of teething infants show no symptoms.

Fine Motor Development: Voluntary Reaching and Grasping cont.

• Early Experience and Voluntary Reaching

– Trying to push infants beyond their current readiness to handle stimulation can undermine the development of important motor skills.

– As infants’ and toddlers’ motor skills develop, their caregivers must devote more energies to protecting them from harm.

MOTOR DEVELOPMENTThe Sequence of Motor Development

– Gross motor development refers to control over actions that help an infant move around in the environment, such as crawling, standing, and walking.

– Fine motor development involves smaller movements such as reaching and grasping.

– Although the sequence of motor development is fairly uniform across children, there are large individual differences in rate of motor progress.

– Motor control of the head precedes control of the arms and trunk which precedes control of the legs (cephalocaudal trend).

– Head, trunk, and arm control appears before coordination of the hands and fingers (proximodistal trend).

The Sequence of Motor Development

Cultural Variations in Motor Development

• Cross-cultural research shows that early movement opportunities and a stimulating environment contribute to motor development.

• Cultural beliefs vary concerning the necessity and advisability of deliberately teaching motor skills to babies.

• Early motor skills are due to complex transactions between nature and nurture.

Fine Motor Development: Voluntary Reaching and Grasping

• Voluntary reaching plays a vital role in infant cognitive development, since it opens up a whole new way of exploring the environment.

• Motor skills start out as gross activities and move toward mastery of fine movements.

• Prereaching is the uncoordinated, primitive reaching movements of newborns.

Fine Motor Development: Voluntary Reaching and Grasping

• Development of Voluntary Reaching and Grasping

– Voluntary reaching appears at about 3 months and gradually improves in accuracy.

– Early reaching is controlled by proprioception, our sense of movement and location in space that arises from stimuli within the body.

– The ulnar grasp is a clumsy grasp of young infants, in which the fingers close against the palm.

– The pincer grasp is a well-coordinated grasp that emerges at the end of the first year, involving the oppositional use of the forefinger and thumb.

Vision– By 2 months, infants can

discriminate colors across the entire spectrum.

– By 3 months, infants can focus on objects and discriminate colors about as well as adults can.

– By 6 months, their visual acuity is about 20/100.

– By 11 months, visual acuity reaches a near-adult level.

– Depth Perception

• Depth perception is the ability to judge the distance of objects from one another and from ourselves.

• The visual cliff was used in the earliest studies of depth perception.

• Research indicates that around the time that infants crawl, most distinguish deep and shallow surfaces and avoid dangerous-looking drop-offs.

Hearing

– During the first year, babies start to organize sounds into complex patterns.

– By 6 months of age, babies “screen out” sounds that are not used in their own language..

– In the second half of the first year, infants focus on the larger speech units crucial for figuring out meaning. Older infants can also detect clauses and phrases in sentences.

– Between 7 and 9 months, infants have begun to analyze the internal structure of sentences and words.

Shaken Baby Syndrome

• Shaking or jerking babies• Swinging up and down

SIDS

• Leading cause of infant mortality: 1/3 of deaths in US

• Usually show physical problems from beginning• More premature, low birth rate, Apgar,• Often have a mild respiratory failure• Chemical abnormality in brain center for

breathing• Smoking• Sleep on back with light covering

Video

Emotional and Social Development

• Social Smile: Smiling elicited by social stimuli; not exclusive to seeing parents• Self-Awareness: Awareness of oneself as a person; can be tested by having infants look in a mirror and see if they recognize themselves• Social Referencing: Observing other people to get information or guidance

Figure 3.4

Figure 3.8

Mary Ainsworth and Attachment

• Separation Anxiety: Crying and signs of fear when a child is left alone or is with a stranger; generally appears around 8-12 months• Quality of Attachment (Ainsworth)• Secure: Stable and positive emotional bond

Mary Ainsworth and Attachment (continued)

• Insecure-Avoidant: Tendency to avoid reunion with parent or caregiver

• Insecure-Ambivalent: Desire to be with parent or caregiver and some resistance to being reunited with Mom

• Contact Comfort: Pleasant and reassuring feeling babies get from touching something warm and soft, especially their mother

Bowlby’s Attachment Phases• Preattachment: Birth to 6 months

– Infant send signals to adult for contact, grasping, crying, or gazing into adults eyes

• Phase 2: 6 weeks to 6-8 months– Signal intensify and focus on caregiver. Still friendly

to strangers, but respond differently• Phase 3: 6-8 months to 18 months-2 years

– More active in seeking and following caregivers. Show separation anxiety

• Phase 4: 18 months-2 years and on– Infants form reciprocal relationships with parents and

significant people in their life

Figure 3.11

Play and Social Skills

• Solitary Play: When a child plays alone even when with other children• Cooperative Play: When two or more children must coordinate their actions

Optimal Caregiving

• Proactive Maternal Influences: A mother’s warm, educational interactions with her child• Goodness of Fit (Chess & Thomas): Degree to which parents and child have compatible temperaments• Paternal Influences: Sum of all effects a father has on his child

Height & Weight Growth

The greatest height & weight increases occur during the 1st year of life, but children continue to grow through infancy & toddlerhood.

• Average birthweights (progression through the 1st 2 years)

--By age 5 months, the average infant's birthweight has doubled to about 15 pounds. --By age 1, the infants' birthweight has tripled to approximately 22 pounds. --By the end of its second year, the average child weighs four times its birthweight. --By age 1, the average baby stands 30 inches tall. --By the end of the second year the average child is three feet tall.

Decreasing Proportions…At birth, the head is ¼ of the neonate’s body. By adulthood, it is only 1/8th the size of the body.

Not all parts of the body grow at the same rate.

The 4 Major Principles Governing Growth1) The CEPHALOCAUDAL PRINCIPLE

states that growth follows a pattern that begins with the head and upper body parts and then proceeds to the rest of the body.

2) The PROXIMODISTAL PRINCIPLE states that development proceeds from the center of the body outward.

(Major Principles Governing Growth continued)

3) The PRINCIPLE OF HIERARCHICAL INTEGRATION states that simple skills typically develop separately and independently but are later integrated into more complex skills.

4) The PRINCIPLE OF INDEPENDENCE OF SYSTEMS suggests that different body systems grow at different rates.

Development of Body Rhythms

• Behavior (sleeping, eating, crying, attending to the world) becomes integrated through the development of various body RHYTHMS (repetitive, cyclic patterns of behavior)– Some rhythms are obvious/easy to notice

• The change from being asleep to being awake/breathing patterns

(development of body rhythms, continued)

– Some rhythms are more subtle• Jerking suddenly while sleeping*Some are apparent right after

birth, others emerge over the course of the 1st year as the nervous system becomes more integrated

One of the major body rhythms is an infants state

-- An infant's STATE is the degree of awareness it displays to both internal and external stimulation.

-- Includes various levels of wakeful behaviors (alertness, crying, etc.) and various levels of sleep (active, quiet)

-- Changes in state are reflected in brain waves measured by a device called an EEG, or electroencephalogram.

Temperament and Environment• Temperament: The physical “core” of personality• Easy Children: 40 %; relaxed and agreeable• Difficult Children: 10 %; moody, intense, easily angered• Slow-to-Warm-Up Children: 15 %; restrained, unexpressive, shy• Remaining Children: Do not fit into any specific category