<P> In his theory of Cognitive development , Jean Piaget proposed that humans progress through four developmental stages : the sensorimotor , preoperational , concrete operational and formal operational period . The first of these , the sensorimotor stage `` extends from birth to the acquisition of language . '' In this stage , infants progressively construct knowledge and understanding of the world by coordinating experiences ( such as vision and hearing ) with physical interactions with objects ( such as grasping , sucking , and stepping ) . Infants gain knowledge of the world from the physical actions they perform within it . They progress from reflexive , instinctual action at birth to the beginning of symbolic thought toward the end of the stage . </P>
<P> In his theory of Cognitive development , Jean Piaget proposed that humans progress through four developmental stages : the sensorimotor , preoperational , concrete operational and formal operational period . The first of these , the sensorimotor stage `` extends from birth to the acquisition of language . '' In this stage , infants progressively construct knowledge and understanding of the world by coordinating experiences ( such as vision and hearing ) with physical interactions with objects ( such as grasping , sucking , and stepping ) . Infants gain knowledge of the world from the physical actions they perform within it . They progress from reflexive , instinctual action at birth to the beginning of symbolic thought toward the end of the stage . </P>
according to piaget the second stage of cognitive development is
according to piaget the second stage of cognitive development is
preoperational
preoperational