At around 18-24 months, children begin to enjoy scribbling: they are able to draw a squiggle and tell you that it is a ‘lady’ or a ‘doggie. This is the stage at which children use symbolism, ie representing things with symbols. Language is also a form of symbolism, as well as art.
This has been described by the developmental psychologist Jean Piaget as part of the ‘preoperational reasoning’ stage of child development, beginnning when children are around 2 years old. Children also start to use pretend play at this stage.
In child psychiatry, we use play as a method of communication and ‘therapy’ with children, as play is used by children in the same way as complex language is in adults. A child will explore events that they have experienced, or worries that they have, through play. For example, a child who has been traumatised may act out that trauma with their toys, or a child who is being bullied may reenact this with toy animals.
This developmental stage is a huge leap for children who previously could only express their frustrations directly, such as by crying when upset. It is exciting for both the children and their parents.