The observation that a baby consistently favors one side, such as the right, when being held, carried, or resting is known as lateral preference. This behavior is very common in infants and is generally not a cause for alarm. A baby’s preference for one side can be influenced by a combination of external factors, like the way they are positioned, and internal neurological and muscular development. Understanding the reasons behind this consistent orientation can help parents recognize typical development and know when to seek professional guidance.
How Parental Habits Influence Positioning
A significant factor influencing a baby’s orientation is the parent’s habitual carrying style. Many parents, especially right-handed individuals, hold their infant on their left side to keep their dominant hand free. When carried this way, the baby’s head is often positioned toward the parent’s right shoulder or chest. The baby is positioned to look toward the parent’s right side, turning their head to maintain visual contact with the parent’s face or view the environment. This consistent positioning reinforces a natural preference for turning the head to the right.
Feeding habits also create repeated patterns of neck movement. If a parent always holds the baby in the same arm for bottle-feeding, the infant consistently turns their head in one direction to latch. Similarly, always starting breastfeeding on the same side can establish a favored neck rotation. Even small, repeated actions, like transferring the baby from the crib in the same orientation, encourage a preference for looking in a specific direction.
Innate Sensory and Auditory Preferences in Infants
Beyond parental routines, an infant’s own biology plays a role in why they consistently turn their head to the right. Studies indicate a mild, innate rightward head-turning bias in a majority of newborns. This tendency, present from birth, suggests that a preference for the right side is part of early neurological development, occurring in approximately 65% of infants.
This rightward bias may be linked to the Asymmetrical Tonic Neck Reflex (ATNR), a temporary, primitive reflex present in the first few months of life. When the baby’s head turns to one side, the arm and leg on that same side extend, while the opposite limbs bend, resembling a “fencer’s pose.” This involuntary movement pattern can encourage the baby to rest in the position that feels most natural, which is often the side with the initial bias.
Infants also exhibit a strong auditory bias, particularly toward familiar voices. A baby can recognize their mother’s voice shortly after birth and will often orient toward it. If the parent frequently speaks to the baby while holding them on the left hip or shoulder, the baby may turn their head toward the source of the sound, which places the parent’s face and voice on the baby’s right side. This turning action is an active attempt to engage with the most important sounds in their world.
The infant’s visual-motor system is highly attuned to the caregiver’s face. If the parent’s face or another interesting visual stimulus (like a window) is consistently located on the right, the baby will naturally look that way. Since the auditory system is dominant in early months, the combination of a preferred sound and visual target on one side strongly reinforces the turning habit.
Addressing Positional Asymmetry and When to Consult a Pediatrician
While a mild preference is common, a persistent, rigid tendency to turn the head only to one side can lead to positional asymmetry. This consistent pressure on one area can result in an uneven head shape, known as deformational plagiocephaly, or “flat head syndrome.” The soft, malleable bones of the infant skull are susceptible to this flattening if the pressure is not relieved through variation in positioning.
To counteract a developing preference, parents can use several strategies to encourage turning to the non-preferred side:
- Counter-positioning involves placing the baby in the crib so that desired visual or auditory stimuli, such as the parent entering the room, are on the side the baby typically avoids.
- Alternate the side on which the baby is held for feeding or carrying to promote a more balanced range of motion in the neck.
- Offer supervised tummy time frequently throughout the day, even for short intervals, to strengthen neck and shoulder muscles.
- Encourage the baby to lift and turn their head in both directions against gravity during tummy time.
If the preference is difficult to overcome or appears rigid, it may signal congenital muscular torticollis (CMT). This condition involves a tightness or shortening of the neck muscles, restricting the baby’s ability to turn their head fully to the opposite side. If a baby consistently struggles to turn their head both ways, shows a head tilt, or develops a noticeable flat spot, consult a pediatrician. Early intervention, often involving physical therapy, is important for addressing muscle tightness and preventing complications.