As william is laying his infant down in the crib at bedtime, he gently removes his hand from the back of the baby’s head and neck, and the baby thrusts its arms outward, appearing to grasp onto something. this is known as the reflex.

This is known as the moro reflex

Explanation:

Moro's reflex is a normal reflex in every newborn baby, characterized by abduction and sudden extension of the upper limbs, usually associated with similar lower limb movement and loud crying. Usually occurs when the child rests his back on a surface, or when there are movements of the surface itself.

This reflex is most intense in the first three months of life. Some babies may keep it for some time, and even adults may have it when they get stronger stimuli. Usually the reflex is followed by rapid opening of the arms, sometimes also the legs, and usually very loud crying that may be prolonged.