Assimilation and accommodation: Piaget theorized that human development is driven by adaptation to the environment through processes called assimilation and accommodation. New experiences or interactions with objects allow the child to form schemas. It can be useful to think of schemas as separate compartments or cubbyholes into which the child can file away information. When encountering new information, some aspects of it can be assimilated into the existing compartments, while other aspects might not fit. The child has to make adjustments to the existing compartments or build new ones in order to accommodate these aspects. Piaget associated play with assimilation because, through play, the child can create a world to their liking. He identified accommodation with imitation; for example, a child pretending to be a dog accommodates when he or she barks like a real dog. When children accommodate new information into existing schemas, play also gives them an opportunity to practice and work through this new information. 

Leading Activity: Vygotsky believed that play was an activity that led the child’s development or enhanced the child’s developmental accomplishments and developed higher mental functions such as focusing their attention, memory, and symbolic thought. For example, if a group of children is creating roadways out of blocks and pretending to drive vehicles on them, Vygotsky would say that this play is allowing children to use symbols to represent their ideas, focus on a task, and develop other higher mental functions.

Socio-dramatic play: Socio-dramatic play is also commonly called pretend play or imaginary play. While this term is used by many theorists, Vygotsky developed three features of socio-dramatic play: children create an imaginary situation, they assume and act out roles, and they follow rules determined by those roles.

Adaptive variability: In this theory, Sutton-Smith connects play with evolutionary and neurodevelopmental theories. There are three principles of variability: flexibility, abundance (which refers to the body’s ability to produce an abundance of brain synapses, and symbolic play. Each principle allows for different possibilities in play and learning.