Experts agree that play is essential for the psychological development of children. In fact, it is considered so crucial that it is listed as one of the rights of children in the United Nation's Convention on the Rights of the Child. Paragraph 1 of Article 31 says:
States Parties recognize the right of the child to rest and leisure, to engage in play and recreational activities appropriate to the age of the child and to participate freely in cultural life and the arts.
For children ages 2 to 6, play promotes psychological development in a social context. When children are 2 years old, they generally watch other children play but do not join in. Gradually they begin to partake in parallel play, which means that they play by themselves alongside other children. They may become involved in associative playing, which means that they use the same toys or equipment but do not directly interact. This leads them, by the age of 4 and older, to begin to participate in cooperative play.
Another important type of playing to psychological development is make believe or pretend play, which has numerous benefits especially for children ages 2–6. For instance, make believe leads to more complex language usage, including the use of more advanced forms of grammar. It also promotes individualism, or awareness that a child's thoughts are unique.
Fantasizing and make believe allow children to express feelings both positive and negative. Using toys to imagine various friends or scenarios enables children to learn to self-regulate their emotions and learn communication skills, empathy, and problem solving.
Children that engage in imaginative play often show impressive creative performances when they are older. According to studies, people who have gone on to acquire genius grants and Nobel Prizes as adults are more likely to have played pretend and make believe games when they were young.
Studies also show that guided play activities in school and at home promote literacy and psychological maturity by encouraging development of vocabulary, manners, and general information.