Children’s mirror writing: 145 years of erring ways and, perhaps, an explanation.

Mirror writing, probably because of the curiosity it arouses, has led to many explanatory theories, even when we restrict ourselves to the population of children. Before the neurological process of mirror generalization – which leads to the non-distinction in memory of an image and its mirror – was well established, theories that ignored it could only be erroneous: the limitation to left-handed writing, retinal inversion, or crossing the midline. However, even subsequent theories that inadequately take it into account or lack generality are no longer viable today.

The explanation we propose, on the other hand, integrates mirror generalization as a fundamental and necessary first step. But then it also integrates an almost equally fundamental aspect, namely the way in which typically developing children form and learn to form the characters (letters and digits).