The Developing Person
Through the Life Span 8e
by Kathleen Stassen Berger
Chapter 5- The First Two Years:
Biosocial Development
PowerPoint Slides developed by
Martin Wolfger and Michael James
Ivy Tech Community College-Bloomington
Reviewed by Raquel Henry
Lone Star College, Kingwood
Body Changes
Body Size
• Average weight: double the birthweight by
month 4, triple it by age 1, much of it is fat
• Average height: grow 14 inches from birth
to age 2
These numbers are norms, an average
measurement.
Body Changes
Body Size
• Head-sparing- biological mechanism that
protects the brain when malnutrition disrupts
body growth.
– The brain is the last part of the body to be
damaged by malnutrition.
• Percentile- point on a ranking scale of 0 to
100.
– 50th percentile is the midpoint with ½ the sample
being higher and ½ lower.
Sleep
• Average newborn sleeps 16 hours per day
• Specifics vary due to age, characteristics,
and social environment
• Ample sleep correlates with normal brain
maturation, learning, emotional regulation,
academic success and psychological
adjustment
Sleep
• REM Sleep: Rapid eye movement sleep,
dreaming, rapid brain waves
• Slow-wave sleep: quiet sleep, increases at
3-4 months
• Co-sleeping: custom of parents and
children sleeping in same room, more
common in Asia, Africa and Latin America
than in Western cultures
Brain Development
• Neuron- the billions of nerve cells in the
central nervous system.
• Cortex- the outer layers of the brain.
• Axon- a fiber that extends from a
neuron and transmits
electrochemical impulses from
that neuron to the dendrites of
other neurons.
Brain Development
• Dendrite- a fiber that extends from a neuron
and receives electrochemical impulses
transmitted from other neurons via their
axons.
• Synapse- the intersection between the axon
of one neuron and the dendrites of other
neurons.
• Neurotransmitter- a brain chemical that
carries information from the axon of a
sending neuron to the dendrites of a
receiving neuron.
Brain Development
Transient Exuberance
• The great but temporary increase in the
number of dendrites in an infant’s brain
from birth to age 2
• Enables neurons to connect and
communicate with other neurons
• This is followed by pruning where unused
neurons and misconnected dendrites die
Stress and the Brain
• If it produces too many stress hormones in
infants, the brain will not be able to have
normal stress responses.
• Occurs in infants who are terrified and
experience other forms of stress.
• Can continue to occur when the infant is
an adult
Necessary and Possible
Experiences
Experience-related aspects of brain function:
• Experience-expectant : require basic
common experiences in to develop
normally (i.e. people who love them)
• Experience-dependent: these happen to
some infants but not all, not necessary for
brain function (i.e. language baby hears)
Brain Development
• prefrontal cortex: the area for anticipation,
planning, and impulse control
• Shaken baby syndrome- a life-threatening injury
occurring when an infant is forcefully shaken back
and forth, rupturing blood vessels and breaking
neural connections .
• Self-righting- inborn drive to fix a developmental
deficit
– All people have self-righting impulses for physical
and emotional imbalances.
Sensation and Movement
• Sensation- The response of a sensory
system (eyes, ears, skin, tongue, nose)
when it detects a stimulus.
• Perception- The mental processing of
sensory information when the brain
interprets a sensation.
• Sensory development- typically precedes
intellectual and motor development
Sensation and Movement
Hearing develops during the last trimester of
pregnancy and is already quite acute at birth;
the most advanced of the newborn’s senses.
Vision is the least mature sense at birth.
– Newborns focus only on objects between 4
and 30 inches away.
– Binocular vision, the ability to coordinate the
two eyes to see one image, appears at 3
months.
Smelling, Tasting, and Touching
• Function at birth and adapt to social world
• Babies recognize each person’s smell and
handling
• Basic Infant Care differs by culture
– Massage important in some cultures
• Infant senses function to help babies join
the human family
Sensation and Movement
• Gross motor skills- Physical abilities
involving large body movements, such as
walking and jumping.
• Fine motor skills- Physical abilities
involving small body movements,
especially of the hands and fingers, such
as drawing and picking up a coin.
Gross Motor Skills
Ethnic Variations
• Gene differences in different ethnic groups
• Cultural patterns of child rearing affect
sensation, perception, and motor skills
Surviving in Good Health
• About 10 billion babies were born 19502010 worldwide
• More than 2 billion died before age 5
• Immunization has saved many people
– The risks of diseases are far greater than the
risk from immunization.
Surviving in Good Health
Surviving in Good Health
Surviving in Good Health
Nutrition
• For every infant disease (including SIDS),
breast-feeding reduces risk and malnutrition
increases it.
• Breastfed babies are less likely to develop
allergies, asthma, obesity, and heart disease.
• As the infant gets older, the composition of
breast milk adjusts to the baby’s changing
nutritional needs.
Malnutrition
• Protein-calorie: when not enough food of
any kind is consumed
• Stunting: being too short for your age due
to severe and chronic malnutrition
• Wasting: being very underweight due to
malnutrition
Malnutrition
• Marasmus: severe malnutrition during
infancy where child stops growing, tissues
waste away and then usually dies
• Kwashiorkor: disease of chronic
malnutrition during childhood where child
becomes more likely to get other diseases
such as measles, diarrhea and influenza