The psychologist Jean Piagetmade a theory in which he proposed that children since the birth begin cognitive development, this process is related to the interaction of the child's environment and its biological development, so Piaget divided the cognitive development into four stages according to the age of the child.
Piaget mentioned that at each stage the child generally presented a skill that was developing more according to his growth, for example in the case of Enid he presents a smile through the stimulation of the sound the rattle but cannot yet take it, so she displays the characteristics of a two-month-old child in the sensorimotor stage; reacts to a stimulus, but cannot hold objects alone.
Sarah is in Piaget's substage of "<span>secondary circular reaction".</span>
In this
substage, the youngster turns out to be more centered on the world and starts
to deliberately rehash and repeat an activity with a specific end goal to
trigger a reaction in environment. For instance like in the given case hit it
to get a specific reaction.
<span>There
is a change in quantity demanded as price changes. When something gets
cheaper, we have extra money left over in which we might buy more of
that item.</span>