Primitive Reflexes

Wikipedia has a list and explanation of primitive or infantile reflexes:

Adult humans have many reflexes, but there are some very interesting ones that are specific to them in the first year of life. These reflexes disappear (or are inhibited) later, as the child moves through a normal course of child development. These primitive reflexes are also called infantile reflexes, infant reflexes, or newborn reflexes.

The frontal lobes are responsible for suppressing these primitive reflexes in adults, but the reflexes begin in the brain stem.