Mirror writing is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of normal writing: it appears normal when it is reflected in a mirror. It is sometimes used as an extremely primitive form of cipher. The most common modern usage of mirror writing can be found on the front of ambulances, where the word "AMBULANCE" is often written in very large mirrored text, so that drivers see the word the right way around in their rear-view mirror—and understand why they hear a loud siren behind them.

Research suggests that the ability to do mirror writing is probably inherited and caused by atypical language organisation in the brain.It is not known how many people in the population inherited the ability of mirror writing (an Australian researcher estimates the proportion to be 1 in 6500. Half of the children of people with the ability inherited it. There are more left-handed mirror writers than right-handed ones, probably because left-handed people tend to have atypical language centres in their brain.

Young children, on first learning to write, are encouraged to start writing at the top left hand corner of a page. If, left to their own devices, they begin at the bottom right hand corner, they write in Mirror writing. A child who produces Mirror writing by starting to write at the bottom left hand edge of a page will immediately change to 'normal' writing when directed to start again from the top left hand corner of the page.


[edit] Notable examples

Wikipedia in Leonardo's style.Leonardo da Vinci is famous for having written most of his personal notes in mirror, only using standard writing if he intended his texts to be read by others. There are two popular theories on why he did this. Leonardo da Vinci was left-handed, causing the ink to smudge easily if he wrote in standard writing. He may also have wanted to protect his ideas from theft or hide them from the Roman Catholic Church (with whom his scientific findings sometimes collided). However, the latter idea, popular among conspiracy theorists, is highly unlikely: it is (and was even at the time) clear, even to a child, that the text in question could be easily read "backwards" (either directly or through its reflection, such as in a mirror). The true purpose of this practice thus remains unknown. A third theory is that he taught himself to write: this would, having regard to the propensity of children to start writing from the bottom left hand corner of a page, have lead him to produce mirror writing.