Which statement about primitive reflexes in newborns is true?

Which statement about primitive reflexes in newborns is true?

• A. Babinski reflex typically disappears by 4 months
• B. Babinski reflex lasts until about 1 year
• C. Babinski reflex is never present
• D. Babinski reflex is not a primitive reflex

Answer: (B)

Primitive reflexes reflect immature brain pathways and fade as the nervous system matures. The Babinski reflex is a classic example: when the sole is stroked along the outer edge toward the toes, an infant may extend the big toe and fan the other toes. This response is normal in newborns and young infants and gradually disappears as corticospinal tracts mature, typically by about one year of age (though it can persist a bit longer in some children). So, saying it lasts until about one year fits the usual developmental timeline. Disappearing by four months is earlier than the typical course, so that statement isn’t consistent with common development. The reflex is not never present in infants, and it is indeed a primitive reflex, so saying it isn’t one would be incorrect.

Primitive reflexes reflect immature brain pathways and fade as the nervous system matures. The Babinski reflex is a classic example: when the sole is stroked along the outer edge toward the toes, an infant may extend the big toe and fan the other toes. This response is normal in newborns and young infants and gradually disappears as corticospinal tracts mature, typically by about one year of age (though it can persist a bit longer in some children). So, saying it lasts until about one year fits the usual developmental timeline.

Disappearing by four months is earlier than the typical course, so that statement isn’t consistent with common development. The reflex is not never present in infants, and it is indeed a primitive reflex, so saying it isn’t one would be incorrect.