Physical Development in Early Childhood

Children in early childhood are physically growing at a rapid pace. If you want to have fun with a child at the beginning of the period, ask them to take their left hand and use it to go over their head to touch their right ear. They cannot do it. Their body proportions are such that they are still built very much like an infant with a very large head and short appendages. By the time the child is five years old though, their arms will have stretched, and they head is becoming smaller in proportion to the rest of their growing bodies. They can accomplish the task easily because of these physical changes.

Growth and Nutrition in Early Childhood

Growth in early childhood

Children between the ages of 2 and 6 years tend to grow about 3 inches in height each year and gain about 4 to 5 pounds in weight each year. The average 6-year-old weighs about 46 pounds and is about 46 inches in height. The 3-year-old is very similar to a toddler with a large head, large stomach, short arms, and short legs. During early childhood, children start to lose some of their baby fat, making them less like a baby, and more like a child as they progress through this stage. By around age 3, children will have all 20 of their primary teeth, and by around age 4, may have 20/20 vision. Many children take a daytime nap until around age 4 or 5, then sleep between 11 and 13 hours at night.

By the time the child reaches age 6, the torso has lengthened and body proportions have become more like those of adults. It should be noted that these growth patterns are seen where children receive adequate nutrition. Studies from many countries support the assertion that children tend to grow more slowly in low SES areas, and thus they are smaller.^[1][2][3]

This growth rate is slower than that of infancy and is accompanied by a reduced appetite between the ages of 2 and 6. This change can sometimes be surprising to parents and lead to the development of poor eating habits.

Nutritional concerns

According to the Centers for Disease Control and Prevention (CDC), 1 in 5 American children between the ages of 2 and 5 are overweight or obese. The American Academy of Pediatrics (AAP) recommends a number of steps to take to help reduce the chances of obesity in young children. Removing high-calorie low-nutrition foods from the diet, offering whole fruits and vegetables instead of just juices, and getting kids active are just some of the recommendations that they make. Muckelbauer and colleagues (2009) found that increasing water consumption in school-aged children by just 220ml (just under 8 oz) per day decreased the risk of obesity by 31%. Finally, the AAP suggests that parents can begin offering milk with a lower fat percentage (2%, 1%, or skim milk) to 2-year-olds. The switch to lower fat milk may help avoid some of the obesity issues discussed above. Parents should avoid giving the child too much milk as calcium interferes with the absorption of iron in the diet as well.

Caregivers (whether parents or non-parents) need to keep in mind that they are setting up taste preferences at this age. Young children who grow accustomed to high-fat, very sweet, and salty flavors may have trouble eating foods that have more subtle flavors such as fruits and vegetables. Lack of a healthy diet may lead to obesity during this and future stages. Offering a diet of diverse food options, limiting foods with high calories but low nutritional value, and limiting high-calorie drink options can all contribute greatly to a child’s health during this stage of life.

Caregivers who have established a feeding routine with their child can find the normal reduction in appetite a bit frustrating and become concerned that the child is going to starve. However, by providing adequate, sound nutrition, and limiting sugary snacks and drinks, the caregiver can be assured that 1) the child will not starve, and 2) the child will receive adequate nutrition. Preschoolers can experience iron deficiencies if not given well-balanced nutrition.

 Physical Development in Early Childhood

Brain Maturation

If you recall, the brain is about 75 percent of its adult weight by two years of age. By age 6, it is at 95 percent of its adult weight. The development of myelin (myelination) and the development of new synapses (through the process of synaptic pruning) continues to occur in the cortex and as it does we see a corresponding change in what the child is capable of doing. Remember that myelin is the coating around the axon that facilitates neural transmission. Synaptic pruning refers to the loss of synapses which are unused. As myelination and pruning increase during this stage of development, neural processes become quicker and more complex.

Greater development in the prefrontal cortex, the area of the brain behind the forehead that helps us to think, strategize, and control emotions, makes it increasingly possible to control emotional outbursts and to understand how to play games. Consider 4- or 5-year-old children and how they might approach a game of soccer. Chances are every move would be a response to the commands of a coach standing nearby calling out, “Run this way! Now, stop. Look at the ball. Kick the ball!” And when the child is not being told what to do, he or she is likely to be looking at the clover on the ground or a dog on the other side of the fence! Understanding the game, thinking ahead, and coordinating movement improves with practice and myelination. Demonstrating resilience and recovering from a loss, hopefully, does as well.

Growth in the hemispheres and corpus callosum

Between ages 3 and 6, the left hemisphere of the brain, which tends to lag behind in terms of activity during the first 3 years of life, increases inactivity, which correlates with the burst in language skills during this time period. Activity in the right hemisphere grows steadily throughout early childhood and is especially involved in tasks that require spatial skills such as recognizing shapes and patterns. Both sides of the brain work together, however, and there is no such thing as a person being either left-brained or right-brained. The corpus callosum, which connects the two hemispheres of the brain, undergoes a growth spurt between ages 3 and 6 as well resulting in improved coordination between right and left hemisphere tasks.

I once saw a 5-year-old hopping on one foot, rubbing his stomach and patting his head all at the same time. I asked him what he was doing and he replied, “My teacher said this would help my corpus callosum!” Apparently, his kindergarten teacher had explained the process!

Children’s Art

Have you ever examined the drawings of young children? If you look closely, you can almost see the result of development of motor skills, perceptual development, and  cognitive development reflected in the way these images change as pathways become more mature. Early scribbles and dots illustrate the use of simple motor skills. No real connection is made between an image being visualized and what is created on paper.

At age 3, the child begins to draw wispy creatures with heads and not much other detail. Gradually pictures begin to have more detail and incorporate more parts of the body. Arm buds become arms and faces take on noses, lips, and eventually eyelashes. Look for drawings that you or your child has created to see this fascinating trend. Here are some examples of pictures drawn by girls from ages 2 to 7 years.

Motor Skill Development 

Remember that gross motor skills are voluntary movements involving the use of large muscle groups while fine motor skills are more exact movements of the hands and fingers and include the ability to reach and grasp an object. Early childhood is a time of development of both gross and fine motor skills.

Early childhood is a time when children are especially attracted to motion and song. Days are filled with moving, jumping, running, swinging and clapping, and every place becomes a playground. Even the booth at a restaurant affords the opportunity to slide around in the seat or disappear underneath and imagine being a sea creature in a cave! Of course, this can be frustrating to a caregiver, but it’s the business of early childhood. Children may frequently ask their caregivers to “look at me” while they hop or roll down a hill. Children’s songs are often accompanied by arm and leg movements or cues to turn around or move from left to right. Running, jumping, dancing movements, etc. all afford children the ability to improve their gross motor skills.

Fine motor skills are also being refined in activities such as pouring water into a container, drawing, coloring, and using scissors. Some children’s songs promote fine motor skills as well (have you ever heard of the song “itsy, bitsy, spider”?). Mastering the fine art of cutting one’s own fingernails or tying their shoes will take a lot of practice and maturation. Fine motor skills continue to develop in middle childhood, but for preschoolers, the type of play that deliberately involves these skills is emphasized.

Toilet Training

Toilet training typically occurs during the first two years of early childhood (24-36 months). Some children show interest by age 2, but others may not be ready until months later. The average age for girls to be toilet trained is 29 months and for boys it is 31 months, and 98% of children are trained by 36 months (Boyse & Fitzgerald, 2010). The child’s age is not as important as his/her physical and emotional readiness. If started too early, it might take longer to train a child. If a child resists being trained, or it is not successful after a few weeks, it is best to take a break and try again later. Most children master daytime bladder control first, typically within two to three months of consistent toilet training. However, nap and nighttime training might take months or even years.

According to the Mayo Clinic (2016b) the following questions can help parents determine if a child is ready for toilet training:

• Does your child seem interested in the potty chair or toilet, or in wearing underwear?
• Can your child understand and follow basic directions?
• Does your child complain about wet or dirty diapers?
• Does your child tell you through words, facial expressions or posture when he or she needs to go?
• Does your child stay dry for periods of two hours or longer during the day?
• Can your child pull down his or her pants and pull them up again?
• Can your child sit on and rise from a potty chair?

Some children experience elimination disorders that may require intervention by the child’s pediatrician or a trained mental health practitioner. Elimination disorders include: enuresis, or the repeated voiding of urine into bed or clothes (involuntary or intentional) and encopresis, the repeated passage of feces into inappropriate places (involuntary or intentional) (American Psychiatric Association, 2022). The prevalence of enuresis is 5%-10% for 5-year-olds, 3%-5% for 10-year-olds and approximately 1% for those 15 years of age or older. Around 1% of 5-yearolds have encopresis, and it is more common in males than females.