Physical Development in Early Childhood

Study Notes

Body Growth During Early Childhood

Growth in body size peaks in the first two years, then slows down; averages 2-3 inches in height and 5 pounds in weight annually.
Boys are generally larger than girls; growth in body fat declines as children become leaner.
By age 5, children's body proportions resemble those of adults, with improved posture and balance.

Average North American Boy

A typical 5-year-old North American boy measures 43 inches in height and weighs 42 pounds.

Cultural Growth Differences

Children from Asian-Indian backgrounds tend to be smaller compared to their North American counterparts.

Efe of the Republic of Congo

Efe adults are typically under 5 feet tall due to genetic factors and hormonal influences on growth.
By age 5, Efe children are shorter than 97% of North American and European children, reaching puberty and ceasing growth earlier.
Smaller size may help reduce caloric needs amid food scarcity and facilitate earlier childbearing due to high mortality rates.

Skeletal Growth

Between ages 2 and 6, about 45 new epiphyses (growth centers) form in the skeleton as cartilage hardens into bone.
X-rays can be used to estimate children's skeletal age and physical maturity.

Losing Teeth

Girls lose primary teeth earlier than boys; cultural background influences timing.
North American children usually receive their first permanent tooth around 6.5 years, while children in Ghana and Hong Kong get theirs around 6 years.

Brain Growth

The brain grows from 70% to 90% of its adult weight between ages 2 and 6, enhancing physical coordination, memory, language, and logical thinking abilities.

Areas of the Brain During Rapid Growth

The brain undergoes reshaping, particularly between ages 4-5, with certain regions producing nearly double the synapses of adults.

fMRI Evidence

Energy metabolism in the cerebral cortex peaks around ages 4-5, indicating significant brain development.

Plasticity

Overabundance of synaptic connections enhances brain plasticity, allowing children to acquire essential skills despite potential damage in some areas.

Synaptic Pruning

Seldom-stimulated neurons lose their connections, reducing synapse numbers; by ages 8-10, energy consumption levels approach those of adults.

EEG, NIRS, and fMRI Findings

Rapid growth is observed in prefrontal-cortical areas associated with executive functions, including impulse control, attention, and memory.
Left hemisphere activity is high from ages 3-6, while right hemisphere activity increases steadily through childhood.

Left Hemisphere Functions

Responsible for language skills and helps improve children's behavioral control.

Right Hemisphere Functions

Develops spatial skills such as direction giving and shape recognition throughout childhood and adolescence.

Lateralization

Refers to the specialization of brain functions between the left and right hemispheres.

Handedness

Reflects the influence of both genetic and environmental factors on brain lateralization.
Most fetuses show a preference for the right hand; by 6 months, infants exhibit more efficient reaching with the right arm.

Dominant Cerebral Hemisphere

Handedness indicates the greater capacity of one brain hemisphere for skilled motor actions.

Handedness in Western Nations

Displays patterns reflecting the interplay of nature and nurture in brain development and lateralization.

Description

This quiz covers the key aspects of body growth during early childhood, focusing on the growth patterns, average height and weight changes, and differences between boys and girls. Learn how rapid growth transitions into a slower rate and how body composition changes in early childhood. Perfect for understanding developmental milestones in young children.