Infant Reflexes

Primitive, or developmental, reflexes are automatic motor responses present early in life. They are generated largely through immature brainstem and spinal pathways before voluntary cortical control is fully developed. Rooting and sucking support feeding; grasping and the Moro response help organize early movement and responses to sudden change. As the nervous system matures, cortical control increasingly suppresses these automatic patterns. The reflex does not simply “turn off”; its disappearance reflects a shift from automatic responses toward purposeful, varied movement. For that reason, the examiner looks at more than whether a response is present. Symmetry, strength, quality, and the infant’s overall tone are equally informative. A reflex finding is a screening observation, not a diagnosis. Persistence of selected primitive reflexes beyond the expected period, marked asymmetry, or abnormal muscle tone can signal a neuromotor disorder and requires further assessment rather than a label at the bedside.