Primitive Reflexes

Theis group of reflexes, like the survival reflexes, are present at birth. Unlike the permanent survival ones, primitive reflexes disappear or become voluntary after infancy.

Rooting - Also considered a survival reflex, this refers to how a baby will turn toward a touch on his or her cheek to try to find the nipple to suck. This reflex is not permanent and becomes voluntary by four months.

Grasping reflex - The newborn’s fingers will curl tightly around an object touching the hand (some babies’ grasps are so strong that they can be lifted off the ground, although testing this is not recommended). Disappears between one and four months.

Stepping reflex - When the baby’s feet are touched to a hard surface, she will lift her feet alternately as if she were walking. Becomes voluntary by four months.

Moro reflex - Also known as the startle reflex, since it appears when a loud noise or sudden position change causes infants to throw their arms wide open and their head back as if preparing to fall. Gone by four to eight months.

Tonic neck reflex - Invoked when the newborn is lying on his or her back. It is also called the fencer’s reflex, since the infant extends the arm and leg on the side to which his/her head is turned while the other arm and leg flex. Becomes voluntary between one and four months.

Babinski reflex - Also known as the plantar reflex and similar to the grasping reflex, this describes how a newborn’s feet curl in response to stimulation on his or her soles. This reflex may have been useful for babies in the distant past to use hands and feet for clinging. Disappears between eight and twelve months.

Galant reflex - Also known as the swimming reflex, this is shown when a newborn curves his or her body toward the side of the middle or lower back being stroked.

Later Reflexes - A few reflexes appear later than birth but most still disappear eventually. At around two to three months, infants will develop:

• Landau reflex - Babies hold their heads upright and extend their legs when held in a prone position. Disappears between 18 and 24 months.
• Tears - The production of tears when crying (this reflex obviously is permanent).

Between eight and twelve months, babies acquire the following additional reflexes:

• Parachute reflex - Infant throws arms out when lowered quickly in a prone position. Interestingly, this doesn’t appear until new mobility causes infants to develop a fear of heights (see section on The Visual Cliff). Disappears between three and four years.
• The palmar (using whole hand) and pincer grasps (using thumb and forefinger) to pick up small items. Become voluntary between eight and twelve months.