Jean Piaget, a Swiss-born doctor, began his work at the Binet institute, adapting verbal reasoning tests for French children. It took him much of his career to developing his own cognitive-development theory, which was at the time, very unique compared to the dominant behaviorist and psychoanalyst theories. His work didn't reach the United States until the mid-'50s and since then the field has been active with theorists from opposing sides trying to integrate their ideas with Piaget's four stages of childhood development (Rathus, 2004). Jean Piaget's second stage, preoperational, starts at age 2 and continues until about 7. This stage in Piaget's scheme is characterized by inflexible and irreversible mental manipulation of symbols. The child begins to represent words mentally but still has egocentric thought. Children in this stage cannot focus on two aspects of a situation at the same time and therefore lack conservation (Rathus 2004). An important feature of this stage is symbolic play, which represents pre-linguistic skills that support subsequent development (Lyytinen et al., 2001). Through this activity, concepts that children learn are modeled, practiced, and honed. Symbolic play serves to reinforce receptive language skills and build expressive language skills. Play does not come before language skills develop and language skills cannot develop well without play. During this period of development in a child's life, they are not mature enough to learn in a structured manner but this does not mean they don't absorb information. The practical life lessons and language they gather receptively on a day-to-day basis you can see replayed, reinforced, and experimented with during a child's playtime.
             Ungerer and Sigman break play behaviors into four categories. Simple manipulation is defined by instances of mouthing, waving, banging, or throwing a single toy. This type of play starts before the preoperational stage but quickl...