Learning through play has been long recognized as a critical aspect of childhood and child development. Some of the earliest studies of play started in the 1890s with G. Stanley Hall, the father of the child study movement that sparked an interest in the developmental, mental and behavioral world of babies and children. The American Academy of Pediatrics (AAP) published a study in 2006 entitled: "The Importance of Play in Promoting Healthy Child Development and Maintaining Strong Parent–Child Bonds". The report states: "free and unstructured play is healthy and – in fact – essential for helping children reach important social, emotional, and cognitive developmental milestones as well as helping them manage stress and become resilient."[12]

Many of the most prominent researchers in the field of psychology (including Jean Piaget, William James, Sigmund Freud, Carl Jung and Lev Vygotsky) have viewed play as endemic to the human species; indeed, the attributions projected upon an imaginary friend by children are key to understanding the construction of human spirituality and it pantheon(s) of deification (and demonization).

Play is explicitly recognized in Article 31 of The Convention on the Rights of the Child (adopted by the General Assembly of the United Nations, November 29, 1989). which states:

1. 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.
2. Parties shall respect and promote the right of the child to participate fully in cultural and artistic life and shall encourage the provision of appropriate and equal opportunities for cultural, artistic, recreational and leisure activities.

Childhood "play" is also seen by Sally Jenkinson (author of The Genius of Play) to be an intimate and integral part of childhood development. "In giving primacy to adult knowledge, to our 'grown-up' ways of seeing the world, have we forgotten how to value other kinds of wisdom? Do we still care about the small secret corners of children's wisdom?"[13]

Modern research in the field of "affective neuroscience" has uncovered important links between role playing and neurogenesis in the brain.[14] Sociologist Roger Caillois used the word ilinx to describe the momentary disruption of perception that comes from forms of physical play that disorient the senses, especially balance.

In addition, evolutionary psychologists have begun to expound the phylogenetic relationship between higher intelligence in humans and its relationship to play.
Children's Games, 1560, Pieter Bruegel the Elder

Stevanne Auerbach mentions the role of play therapy in treating children suffering from traumas, emotional issues, and other problems.[15] She also emphasizes the importance of toys with high play value for child development and the role of the parent in evaluating toys and being the child's play guide.