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The Newborn Period: A Developmental Perspective on the First Four Months

The first few months of an infant’s life can be both very exciting and very overwhelming for caregivers. The newborn infant exclusively relies on his or her parents and/or caregivers for survival.

The newborn period, birth to four months, is a period when parents and caregivers are working very hard to learn their infant’s signals and respond appropriately to their needs. Infants depend exclusively on soothing and appropriate responses from their caregivers in order to thrive and develop. In fact, there is no possible way to spoil an infant.1 On the contrary, when adults respond to newborns and meet their needs consistently and promptly, children learn to trust their caregivers and realize that they have a positive impact on their world. Children use this trust and these positive experiences to build upon for future development and learning.

The transition from womb to world can be pretty harsh on a newborn. Therefore, caregivers need to be sensitive and patient in soothing and caring for their infants. The first four months of life are sometimes referred to as the “fourth trimester.”2 In these first four months, infants mainly work on maturing their brain and nervous system. They sleep in short stretches, without much focus on whether it is night or day. They are unable to settle themselves and go back to sleep on their own.3 During this time, children need to eat very frequently, at least every two to three hours. Infants cannot soothe themselves and rely on their caregivers to calm them. If infants are born prematurely, this fourth trimester transition is even longer, as premature infants work extremely hard to first reach a healthy state where they can maintain their body temperature, eat successfully, and gain weight.


Children do not come into the world defenseless. They are born with instinctive reflexes designed for basic survival.8 Below is a list of the most common reflexes:

  • Hand-to-mouth reflex: brings fist up to mouth; important for soothing and eating
  • Palmar reflex: closes hand and “grips” a caregiver’s finger when there is a light touch to the palm
  • Protective reflex: turns head from side to side and squirms if an object is coming straight on, e.g., looks away to disrupt eye contact with a caregiver when feeling overwhelmed
  • Rooting reflex: turns head toward the direction of a touched cheek, searches for source of food
  • Sucking reflex: begins to suck when a nipple (either breast or bottle) or finger is placed in the mouth and touches the roof of the mouth

During the first four months, infants rely on their caregivers to keep them organized, calm, and content. This is described as achieving homeostasis, and is where the infant is most comfortable. Homeostasis is not easy to achieve, and caregivers find themselves attempting many different strategies to soothe their infants.4 This may include rocking an infant who is sleepy, or feeding an infant who is hungry. Infants are also using all of their senses to take in stimulation from their environment. However, just as with adults, there is always the possibility of overstimulation, when infants become uncomfortable with the stimuli in their environment. Infants demonstrate overstimulation through behaviors such as gaze aversion, crying, spitting up, or hiccupping.Caregivers need to closely read these signals, and change the environment as needed. This may include reducing noise such as the television or radio, dimming the lights, or wrapping a cold infant in a thicker blanket.

Infants are born with unique personality traits, known as their temperament. The temperament of the infant will influence how caregivers will interact with him or her. In the early months, these traits are visible in how infants sleep, how easy or difficult they are to soothe, how intense their movements are, and how alert they become. The main goal is to understand and recognize the unique traits of infants and respond consistently and thoughtfully. This may mean standing and rocking an infant who has difficulty remaining asleep; or simply laying down an infant who is content in observing his or her surroundings. The more appropriate the response, the calmer the infant.

Nine characteristics of temperament:


  • Activity level refers to the level of children’s physical energy
  • Regularity refers to children’s level of predictability in their biological functions (sleep, wake, eat, eliminate)
  • Approach or withdrawal refers to how children respond to new people and/or environments
  • Adaptability refers to how long it takes children to adjust over time in different situations
  • Threshold of responsiveness refers to how easily a child is disturbed or distracted by sensory changes in the environment.
  • Intensity of reaction refers to the intensity of a positive or a negative response.
  • Quality of mood refers to children’s general disposition: happy or unhappy.
  • Distractibility refers to children’s tendencies to either retain or lose focus when interruptions occur in the environment.
  • Attention span and persistence refers to the length of time children can stay engaged and follow through while engaged in tasks.

As caregivers become more accustomed to the signals, patterns, and temperament of their infants, they will notice that there are times of the day when the infant is sleepy, alert, or fussy. These behaviors are described as states of consciousness.6 There are a total of six states that infants cycle through during the day. While these states may appear to be somewhat consistent, they will most certainly change in the first month of life and for months afterward. The six states of consciousness are:7

  • Deep sleep — able to shut out disturbing stimuli from the environment; breathes deeply, regularly, and heavily
  • Light sleep — sleep is lighter; moves; breathing is shallower and irregular; startles at noises
  • Drowsiness — eyes start to close; may start to doze
  • Quiet alert — bright face, movements are smooth; breathing, face, and body posture all demonstrate interest and attention
  • Active alert — actively moves body and face
  • Crying — cries, becomes disorganized; relies on parent’s attention and intervention.

It is important for caregivers to carefully read the cues that infants are displaying during these states in order to respond thoughtfully. For example, shaking a rattle at an infant who is in the drowsiness state may make him or her increasingly fussy. Both the quiet alert and active alert states are the best time for play and interactions that support learning and development.

Between two and four months, infants undergo many changes. They become more social and interactive. This is first marked by the emergence of the social smile, around six to eight weeks. In addition to smiling, infants begin to coo and gurgle to communicate with caregivers. Reflexes are fading and voluntary movements are more common.

By four months infants will be able to:

  • Raise their head and chest when lying on their stomachs
  • Open and shut hands
  • Take swipes with hands at dangling objects
  • Grasp and shake objects
  • Continue to have an increasing interest in human faces
  • Begin to engage in social interactions
  • Recognize familiar objects and people at a distance.

These first four months are a very special time. Infants are born ready to be social; love, laugh, and interact with them as much as possible. Take advantage of the times when they are alert and ready to engage. Diapering and bathing times are great examples of times when you can engage in social interactions. Sing, hug, rock, coo, smile—all of these are loving interactions that help infants feel secure enough to learn. These early experiences are so important and meaningful; they help encourage bonding, and are the beginning of the important relationship(s) that children need to build strong attachments and thrive in their development.


  1. Brazelton, T. B. (1992). Touchpoints: Your child’s emotional and behavioral development. New York: Perseus.
  2. Karp, Harvey (2002). The happiest baby on the block. New York: Random House.
  3. Shonkoff, J. & Phillips, D. (Eds.). (2000). From neurons to neighborhoods: The science of early childhood development. Washington, D.C.: National Academy Press. Online version
  4. Gillespie, L.G. & Seibel, N. (2006). Self-Regulation: A cornerstone of early childhood development. Beyond the Journal.
  5. Brazelton, T. Berry (1992). Touchpoints: Your child’s emotional and behavioral development. New York: Perseus. *Adapted from Thomas, A. & Chess, S. (1977). Temperament and development. New York: Brunner/Mazel.
  6. Brazelton, T. B. (1992). Touchpoints: Your child’s emotional and behavioral development. New York: Perseus.
  7. Brazelton, T. B. (1992). Touchpoints: Your child’s emotional and behavioral development. New York: Perseus.
  8. Brazelton, T. B. (1992). Touchpoints: Your child’s emotional and behavioral development. New York: Perseus.

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