How do toddlers sometimes write perfectly in mirror image?
When learning to write, the brain stores the movements of joints and muscles in a ‘motor programme’.
Mirror writing is common in children between three and seven years old
Spontaneous mirror writing is common in children between the ages of 3 and 7 years old and appears to be associated with learning to read and write. Mirror writing usually occurs with letters that can be written in mirror image ('b' and 'd'). Occasionally, however, a child will write all the text in mirror image. For most children, writing in mirror image is a phase that passes on its own.
Little research conducted into spontaneous mirror writing
Some people learn two handwriting styles: normal handwriting and ‘conscious’ mirror writing. Two well-known 'conscious' mirror writers are Leonardo da Vinci and Lewis Carroll, who used normal handwriting for letters and mirror writing for their own notes. Although mirror writing is common among children, there has been little research into the subject. What we know, we have mainly learned from 'conscious' mirror writers.
Motor phenomenon
Mirror writing seems to be more common in left-handed people who have learned to write with the right hand and in people who are ambidextrous. Since reading mirror writing is not easier, not even in relation to a text written by the same individual, mirror writing seems to be mainly a motor phenomenon.
‘Motor programme’
When learning to write, the brain stores the movements of joints and muscles in a ‘motor programme’. This programme can likely be used for both hands, but is then mirrored for the non-dominant hand. This would explain why non-mirror writers often find mirror writing easy when they write their name simultaneously with both hands: from left to right with the right hand and from right to left with the left hand. Why not give it a try?