Physical Development in Preschoolers

At age 2:
- Weight: 25-30 pounds
- Height: Approximately 3 feet
At age 6:
- Weight: 36 pounds
- Height: Approximately 46 inches
Observations:
- Arms and legs begin to lengthen during these years.
- Body proportions become more similar to adults by age 6.

Height and weight distinctions between boys and girls arise during the preschool years.
Preschoolers in developed countries are typically taller and heavier compared to those in less developed regions.

Myelination: Increased myelination leads to more interconnections among neurons, enhancing brain function.
Malnourished children exhibit delays in brain development.
Lateralization: The two hemispheres of the brain become more specialized.
- Left Hemisphere: More focus on language processing.
- Right Hemisphere: Greater involvement in emotional expression.
By age 5, children's brains are about 90% of the weight of an adult brain.
Growth Query: It is still debated whether cognitive advances drive brain development or if brain development facilitates cognitive accomplishments.

Improved control over eye movements occurs, but:
- Preschoolers struggle to precisely scan small print necessary for reading, a skill that improves by age 6.
- Auditory acuity also improves; however, preschoolers face challenges isolating specific sounds amidst multiple competing noises.

Sleep issues are prevalent in preschoolers:
- 20-30% experience nights where it takes more than one hour to fall asleep.
- Upon sleeping, most children sleep soundly.
- Nightmares affect 10-15% of preschoolers.
- Night Terror: An intense physiological arousal that causes dramatic awakening in panic.

There was a significant rise in obesity rates among older preschoolers post-1980, but these rates have declined since 2014.
Recommended strategies for healthy nutrition include:
- Consuming a varied diet with iron-rich foods.
- Children develop natural food preferences.
- Just-right Phenomenon: Preschoolers may develop rigid meal routines.

Preschoolers typically experience about 8 colds between ages 3 and 5.
Minor illnesses provide benefits such as:
- Building immunity and helping to develop coping skills.
Socioeconomic status (SES) factors can hinder access to quality healthcare for some children.

Leukemia: The most common cancer in preschoolers, characterized by excessive white blood cell production in the bone marrow.
- 70% of childhood leukemia patients survive.
Approximately 1.2 million children under age 5 died due to healthcare disruption from the Coronavirus pandemic.

Children under age 10 are twice as likely to die from injuries compared to illnesses.
Common types of injuries:
- Falls, burns, drowning, car accidents, exposure to poisonous substances.
Boys tend to have higher injury rates.
Variations in injury rates can exist across different ethnic and cultural groups.

14 million children worldwide are at risk for lead poisoning.
Consequences of lead exposure before age 6 can include:
- Lowered intelligence, deficits in verbal and auditory processing, hyperactivity, distractibility, antisocial behavior, aggression, and even death.
- Low SES families are particularly vulnerable, often due to lead paint and high pollution levels.
Cognitive Test Scores: Increase in lead exposure correlates with lower cognitive test scores among children:
- Low-income groups show particularly significant declines.

After the Flint water crisis, new federal requirements mandate nationwide lead pipe removal to protect child health.
Communities are required to remove lead-containing pipes and service lines within ten years under this new rule.

Steps to reduce injury risks in children include:
- Secure storage of medicines, cleaning solutions, and toxic substances.
- Proper use of car seats.
- Never leaving children unattended, particularly in bathtubs.
- Teach children established safety rules.

By age 3, children develop various gross motor skills such as:
- Jumping, skipping, running.
Development of motor skills is linked to:
- Myelination and the maturation of brain areas responsible for balance and coordination.
Fine Motor Skills: Require practice and are influenced by gender socialization, which shapes the activities boys and girls engage in.

Girls’ motor skills are predictive of children's social skills and their engagement in learning activities.
Fine motor skills are significant predictors of performance in reading and mathematics.