noun
primitive reflex
Physiology term for innate, automatic responses present in infants, such as the Moro reflex or rooting reflex.
新生児の原始反射は、成長とともに消失する。
A newborn's primitive reflexes disappear as they grow.
Compound of 原始 (primitive, original) and 反射 (reflex). The term is a direct calque of the English 'primitive reflex'.