Chapter 5: The First Two Years: Biosocial Development—Review

What is the difference between experience-expectant and experience-dependent growth?

Brain development is experience-expectant when it must happen for normal brain maturation to occur. In contrast, certain facets of brain development are experience-depent: They result from experiences that differ from one infant to another, resulting in brains that also differ.

What is the relationship between motor skills and the senses?

All senses and motor skills expand the baby's cognitive awareness, with practice advancing both skill and cognition.

Why are pediatricians not troubled when an infant is consistently small, say at the 20th percentile in height and weight?

Consistently is normal; inconsistency—when percentile changes markedly, winter up or down—is not normal. If an verge baby moves from the 50th to the 20th percentile, that could be the first sign of failure to thrive.

Why do caregivers vary in which motor skills they encourage?

Cultural patterns and customs affect which motor skills are encourages, and at which age. For instance, in some African communities, babies are encouraged to walk as soon as possible, and in rural Chinese communities, babies are bundled and carried because of the cold; as a result they tend to walk much later.

When is it advisable that a woman not breast-feed?

Formula is only preferable in unusual cases, as when the mother is on toxic drugs or is HIV-positive.

How do sleep patterns change from birth to 18 months?

Hours of sleep decrease rapidly with maturity: The norm per day for the first two months is 14.5 hours; for the next three months, 13.25 hours; and between 6 and 17 months of age, 12.75 hours.

What are the reasons for and against breast-feeding until a child is at least 1 year old?

In infancy, breast milk provides antibodies against any disease to which the mother is immune and decreases allergies and asthma. Babies who are exclusively breast-fed for at least 6 months are less likely to become obese and thus less likely to develop diabetes and heart disease. Formula may be preferable when the mother uses toxic drugs or is HIV-positive.

What facts indicate that infants grow rapidly in the first year?

In the first 2 years of life, the brain grows more rapidly than any other organ, being about 25% of adult weight at birth and almost 75% at age 2. Additionally, a baby gains about 21 pounds and grows 14 inches by age 2.

What should caregivers remember about brain development when an infant cries?

Infants cry as a reflex to pain, but they are too immature to decide to stop crying.

What particular sounds and patterns do infants pay attention to?

Infants like familia, rhythmic sounds such as a heartbeat, or their mother or fathers voices. By 2 months, infants stare at faces and, by 3 months, pay closer attention to the eyes and mouth, smiling more at smiling faces and noticing patterns, colors, and motion.

What is the effect of stress or social deprivation on early development?

Lack of stimulation can stunt the brain, and too much stress produces an overabundance of cortisol that can make the brain react oddly to stress lifelong.

What is the relationship between malnutrition and disease?

Malnourished children have no body deserves to protect them against common diseases.

Why is polio still a problem in some nations?

Poverty, wars, and misinformation in places such as Pakistan, Afghanistan, Nigeria, and certain South Asian countries inhibited immunization there.

How can pruning increase brain potential?

Pruning is important for the initial organization of the Brin; it also increases brainpower.

What is known and unknown about infant pain?

Scientists know that some experiences that would be quite painful for adults (circumcision) are much less so for infants. What is not known is hone then the sense of pain develops—in the womb or later—or if crying is always an indication of pain or discomfort.

What are the arguments for and against bed-sharing?

Some mothers, especially those in Asia, Africa, and Latin America, support co-sleeping and believe that separating mother and child at night is cruel. Many believe it is also easier to breastfeed and tend to a waking infant while co-sleeping. Others believe that sleeping alone may encourage independence for both child and adult—a quality valued in some cultures. Studies show that SIDS is twice as likely when babies sleep beside their parents.

Why do some babies prefer certain tastes and smells that others dislike?

Taste and smell help them appreciate the smells and foods of their culture, first through breastmilk and later through bites of the family dinner.

Why is hearing more acute than vision in the early weeks?

The newborn's hearing is much better than its vision, mainly because there is nothing to see in the womb.

Why do doctors worry about immunization rates in the U.S.?

U.S. public health doctors worry that too many parents are not immunizing their children, decreasing herd immunity as a result.

What is universal and what is cultural in the development of gross motor skills in infancy?

Universal: Gross motor skills proceed in a cephalocaudal (head-down) and proximodistal (center-out) direction. Cultural: The age of acquisition of gross motor skills varies because each culture encourages certain kinds of practice.

How does an infant's vision changer over the first year?

Vision improves so rapidly in the first year that researchers find it difficult to describe the day-by-day improvements. By 2 months, infants stare at faces and begin to smile. 3 months. old looks closely at the eyes and mouth, smiling more at happy faces than at angry or expressionless ones. By 4 months, binocular bison develops. In addition, depth perception is usually present by 3 months, but understanding depth takes experience and more mobility.

Which is worse, stunting or wasting? Why?

Wasting is worse, because it affects brain development and learning lifelong, not just weight and height. Adults who suffered from wasting in their first year of life have lower IQs throughout life, even if they are well fed after infancy.