Four Principals of Growth:
The cephalocaudal principle is the principle that growth follows a pattern that begins with the head and upper body then proceeds down the rest of the body. The word cephalocaudal means
“head to toe.” Basically, we develop better eyesight before we can learn to crawl, stand up, and walk.
The proximodistal principle states that development proceeds from the center of the body outward. The trunk of our body develops before we can develop hands and feet. It also includes the use of these developments. The word proximodistal means “near and far.” For example, we are able to sit up before we can hold a cup.
The principle of hierarchical integration is that we have to master certain skills before we can master others. Simple skills develop separately and independently, but are combined for more complex skills. We cannot grasp something in our hand before we learn how to manipulate our arm movements.
The principle of the independence of systems suggests that different body systems grow at different rates. The length of our bodies grow at a different rate then our nervous system develops.
Physical Growth:
The average newborn weighs just over seven pounds. They grow very rapidly. By five months, their weight has doubled. By their first birthday, their initial weight of seven pounds has tripled to about
22 pounds.
Their weight gains match the length of their bodies. A newborn is about 20 inches, but by age one, they have gained 10 inches to become 30 inches long. By age two, they are about 36 inches long.
Their head weight also varies on age. The head of a newborn is about 1/4 th of its size, but by age two, it’s only 1/5 th . By adulthood, the head is only 1/8 th of the body’s size.
There are also gender differences. Boys tend to weigh more and are slightly taller than girls. Ethnic differences exist as well. Asian infants tend to be slightly smaller than North American Caucasian and African American infants. African American infants also tend to be slightly bigger than North
American Caucasian infants.
The Nervous System:
Neurons are the basic cells of the nervous system. They can communicate with each other chemically by sending neurotransmitters across synapses, or the gap between the neurons.
Newborns are born with more neurons than is necessary, but are weeded out through lack of use and communication. They then die out, which is called synaptic pruning. This allows the other

neurons to become more efficient. As the child gets older, these neurons increase in size and their chains increase in complexity and efficiency.
The environmental influences also have an impact on neural development. This is another case of nature vs. nurture. The brain (a group of highly efficient neurons) has a degree of plasticity.
Plasticity is the ability of the neurons to change due to experience.
For example, there have been examples of brain injury in which other areas of the brain can adapt due to limited functions. In short, one part of the brain can be damaged and other parts of the brain can see to function like the part of the brain that was damaged. This plasticity is greater during infancy than adulthood.
Development of Bodily Systems:
A sensitive period is a limited time period in which an organism is particularly susceptible to environmental influences in terms of development. Babies have a very important sensitive period.
Environmental stimulation is important for development. Parents that cuddle, talk to, hold, and read to their infants stimulates multiple senses and increases the tendency for learning.
Behavior can influenced by state. State is the degree of awareness in both internal and external stimulations. These states are levels of wakeness and alertness. Sleep is a huge state in infants. On average, newborns sleep 16 to 17 hours a day. However, babies do not sleep as adults sleep. They sleep in fits of wakefulness that last for about two hours at a time. By 16 weeks, infants begin to sleep for six hours a night. By the end of the first year, they can sleep through the whole night.
REM stands for rapid eye movement. It is the period of sleep that is found in older children and adults and is associated with dreaming. Even though it is thought that babies do not dream, it is a way that infants stimulate themselves. This is called autostimulation, which is important for infants.
Most sleep stages are determined by nature, but there are many environmental circumstances that can impact sleep patterns. Heat waves, cold temperatures, and rainstorms can all play a part in sleep cycles. Culture can also play a part in sleep patterns. In certain cultures, mothers and babies sleep together. Because of this, newborns often breast feed at night and this changes their sleep schedule.
Parents in the United States let their infants sleep for longer periods of time and this can change their sleep patterns as well.
SIDS:
SIDS (Sudden Infant Death Syndrome) is the unexplained death of a healthy infant. It effects about one in 1000 infants each year. It’s a peaceful death, with no apparent suffering. They just simply cease to breathe.
There has been studies on this condition, but there has been no conclusive evidence as to what causes these poor infants to die. However, they do know that there are contributing factors to this

condition. Low birth weight, prematurity, the mother smoking during pregnancy, and child abuse contribute. There aren’t many preventative measures for this condition.
Shaken Baby Syndrome:
This is a form of child abuse where the infant is shaken due to anger or exasperation on the part of the caregiver. It rotates the brain in the skull, causing blood vessels and neuron chains to tear and can lead to severe mental and physical defects. It could also lead to death.
The Basic Reflexes:
Reflexes are unlearned, involuntary responses that occur in response to certain stimuli. It helps them adapt to their new surroundings. They help establish certain behaviors for the future and get rid of others.
Some reflexes are used throughout the process of life. The blink reflex keeps the eyes from drying out and helps prevent damage to the retina by blocking out direct light. The gag reflex prevents choking by clearing the throat.
Reflexes lead to more complex motor development. However, there is no indication that purposeful practicing of these reflexes will lead to better motor skills. In fact, it can harm the infant, causing muscle strain, broken bones, and dislocated limbs.
Reflexes can also be used to predict a child’s development. Pediatrician and human growth specialists can tell when something may be amiss in the child’s development. Reflexes appear and disappear at regular intervals and this can indicate lags in the infant’s development.
Fine and Gross Motor Skills:
Fine and gross motor skills show the change from a helpless infant to one with skills to survive in the world in the future. These begin with gross motor skills. These slowly develop and lead to crawling, walking, and sitting up. Crawling typically begins around eight to ten months, walking around twelve to fourteen months, and sitting up by the age of six months.
Fine motor skills is the ability for an infant to coordinate movement in their limbs. By three months, some limb coordination is evident. Over time, their fine motor skills continue to develop and become more sophisticated. Dynamic systems theory describes how motor behaviors are assembled. Motor behaviors require coordination of muscles, perception, cognition, and motivation.

Most of what we are basing reflexes and motor development are norms. Norms are the average performance of a child at a given age. They come from a large sampling of children. The Brazelton
Neonatal Behavior Assessment Scale is a measure of the norms. It determines infants’ neurological and behavioral responses to their environment. They are based on data from a wide range, heterogeneous, culturally diverse set of children.
Cultural differences also arise in norms. African American infants typically tend to show more rapid motor development than Caucasian infants. Ache infants (a people that live in the rainforests of
South America) are not allowed to venture more than a few feet away from their mothers and almost always have direct contact with their mothers. Kipsigis infants are subjected to much more activity and exercise than other infants in the world. They are put into round holes in the ground to promote sitting up and are started to be taught to walk within eight to ten weeks after birth.
Nutrition:
In general, infants should consume about fifty calories per pound for each pound they should weigh.
Malnutrition is the condition of having an improper balance of nutrients. It can effect both first and third world countries. Children who are chronically malnourished tend to score lower on IQ tests and school assessments. Malnourishment during the first year can lead to marasmus, a disease in which infants stop growing and kwashiorkor, a disease in which a child’s body and face swell with water to help the body process with what little nutrients it has.
Nonorganic failure to thrive is a disorder where infants stop growing due to lack of stimulation and attention. As many of a quarter of American infants and children under five have diets that fall below the minimum caloric intake. Thankfully, it can usually be reversed within the first eighteen months of life.
Obesity is defined as weight greater than twenty percent above the average for a child’s height.
Overweight babies are more likely to have weight problems as adults. The old adage “a fat baby is a healthy baby” is not always correct. Parents should focus less on weight and more on nutrition.

History and culture differ greatly on the practice of breastfeeding. In the Egyptian, Greek, and
Roman empires, women usually fed only their own children. However, breastfeeding began to be seen as something too common to be done by royalty, and wet nurses were employed to breastfeed the children of the royal families. This extended over time, particularly in western Europe, where noble women often made use of wet nurses. But lower class women breastfed their babies and used a wet nurse only if they were unable to feed their own infant. During the early 1900s, breastfeeding started to be viewed negatively by Western societies, especially in Canada and the United States.
These societies considered it a low class and uncultured practice. This coincided with the appearance of improved infant formulas in the mid nineteenth century and its increased use, which accelerated after World War II. From the 1960s, breastfeeding experienced a revival which continues to today.
Today, most doctors think that for the first twelve months of life, there is no better food for an infant than breast milk. Breast milk is nutrient rich and offers immunities to assorted childhood diseases, like allergies, ear infections, and respiratory diseases. There is even some evidence to suggest that breast milk may enhance cognitive function.
It also creates a significant bond between mother and child. Infants are more responsive to their mothers’ touch. It can even enhance the mother’s health. Research suggests that women who breastfeed may have lower rates of ovarian cancer and breast cancer prior to menopause.
However, breastfeeding is not a cure-all for newborn nutrition. If you were raised on formula, you have not suffered irreparable harm. Enriched formula has come such a long way. It used to be just cow, donkey, or goat milk with a little flour added. Some mothers opt out of breastfeeding for various reasons. In conclusion, though, “Breast is Best.”
Breastfeeding cannot sustain babies alone. At around six months, they can start eating solid foods, even though they aren’t need until around nine to twelve months. Solid foods should be introduced gradually to allow awareness of preference and allergies.

Weaning, or the gradual completion of breast or bottlefeeding, is greatly debated about. When weaning starts varies from parent to parent. The American Academy of Pediatrics recommends that infants should be breastfed or bottlefed for the first twelve months. Some parents do it as early as three months, while others wait for to two to three years or even more to start weaning.
Visual Development:
Sensation is stimulation of the senses. Perception is the mental process of sorting out this stimuli.
Visual perception changes rapidly in infants. Just a few short hours after birth, a baby will prefer its own mother’s face to other faces. A newborn can only see about twenty feet. By six months, they can see as well as an average adult. Depth and motion are perceived around fourteen weeks.
It has been proven that infants prefer to see complexities rather than simple. Babies have preferences about what they want to see. Statistically, they prefer curved lines over straight lines, three dimensional to two dimensional, and human faces to nonhuman faces.
Auditory Perception:
Infants hear from the time of birth. In fact, the fetus responds to sounds outside the womb. Because they have practiced hearing, their auditory perception is actually better than most people would think it would be. Infants are more sensitive to very high and very low frequencies, much better than adults, and usually have less sensitivity listening to middle-range frequencies. However, sound
localization, or pinpointing where a sound comes from, is harder for infants because they have smaller heads and are at a disadvantage.
By four months, infants can discriminate their own name from similar sounding words. It is suggested that exposure to sound in the wombcan impact their preference for the voice of their mother. By one year, they hear to about the equivalent of an adult.

Smell and Taste Development:
A newborn has a keen sense of smell. Some newborns only a couple weeks old can distinguish their mother’s smell. Breastfeeding increases this skill. Unfortunately, this doesn’t extend to the father.
They also have a very developed sense of taste. They even prefer sweet food and show preference for what their mother ate during pregnancy. That doesn’t mean that they won’t like something that their mother didn’t eat during pregnancy; it just means that they might have a preference for something that their mother ate.
Sensitivity to Pain and Touch:
Babies are born with the capacity to feel pain. It is not sure if it is the same way we feel pain in adulthood, but babies show similar signs of distress. Those signs include increased heartbeat, sweating, facial signs of discomfort, and change the intensity of crying.
Research advocates that exposure to pain in infancy may lead to a higher sensitivity to pain in adulthood. Because of this and other reasons, medical experts now endorse the use of painkillers and anesthesia for surgeries, including circumcision.
Touch is a source of sensation for an infant and is highly defined. Many of the reflexes require touch to take effect. The rooting reflex needs touch to be able to complete its purpose.