Why Kids Write Letters Backwards: Correct It or Wait?

In 2014 the American psychologist Rebecca Treiman and her colleagues published a study in which 130 children aged five and six wrote letters of the alphabet, and the researchers looked at how often they wrote them the wrong way round. Letters that face left, such as d and J, were reversed far more often than letters that face right, such as b and C. And the number of reversals a child made was not related to how well that child read about two years and nine months later.

When a child writes a 3 or an S backwards, parents tend to worry. In this post I go through what research says about why mirror writing happens, and then give my own view on how long to wait, what to say at home, and when it is worth asking someone.

What mirror writing is

Mirror writing is a letter or number written the wrong way round, as if seen in a mirror. Sometimes the whole character is flipped, and sometimes only part of it. It happens with letters and numbers, and in Japanese with hiragana and katakana too.

It is not unusual for a child who is just learning to write. The French researcher Jean-Paul Fischer and his colleagues have studied mirror writing in typically developing children for many years, and they report that five- and six-year-olds reverse even letters and numbers they have never been taught (Fischer and Luxembourger, 2018 review).

Why children write the wrong way round

There is no single cause, but research mainly offers two explanations.

We see mirror images as the same thing

Our eyes and brain are built to treat an object and its mirror image as the same object. A cup with its handle on the right and a cup with its handle on the left are both a cup. For recognising things, that is very useful.

For letters it is a problem, because b and d, or p and q, become different letters when flipped. In a 2010 study, the French neuroscientist Stanislas Dehaene and his colleagues argued that the brain area we recruit when we learn to read has this same tendency to treat mirror images as equal, and that this may explain the mirror errors children make for a while. To read and write, we have to learn to switch that tendency off for letters.

Children remember direction with a rule of thumb

The second explanation is about how direction is stored. In Treiman’s study, letters that face left were the ones most often reversed. More letters in the Latin alphabet face right than left, and the authors suggest that children pick up, without realising it, a sense that “letters face right”, and then turn left-facing letters to the right as well.

Something similar has been reported for numbers. In Fischer’s series of studies, left-facing digits such as 1, 2, 3, 7 and 9 are the ones most often reversed. The symmetrical 0 and 8 are almost never written wrongly. Fischer also suggests that children can tell the orientation of a character when they look at it, but the direction tends to drop out when they write it from memory. In other words, reversals are more likely when writing without a model than when copying one.

People sometimes blame left-handedness, but in Fischer’s research left-handed children were not more likely to mirror-write than right-handed ones.

How long to wait

Most of the research looks at children between four and six, and treats mirror writing at that age as normal. Because it is part of learning letters, there is no age by which it must disappear.

Understood, an American site about learning differences, says that reversing letters is not on its own a sign of dyslexia, and that a child who still often reverses letters by the end of first grade may be worth having evaluated.

In Treiman’s study, what predicted later reading was not the number of reversals but how many letters a child could write correctly overall. So I think it matters more to look at the whole picture than to count reversals. If several of the following come together, I think it is reasonable to talk to the child’s teacher, your doctor, or a local child development service.

• After about a year of school, the child still reverses the same letters again and again
• Reading is a real struggle, and letter sounds or names are slow to stick
• The child finds the shapes of letters hard to remember, and even copying from a model goes wrong
• There are other concerns besides mirror writing, in speech or in fine motor skills

I am not a medical or developmental specialist. If you are worried, please do not decide alone; ask someone who is.

What to say at home

What follows are my suggestions based on the research above. They are not methods that have been tested in studies.

Do not just say “that’s backwards”. Often the child cannot see that the letter is reversed. Being told “wrong” or “backwards again” does not tell them what to change. Saying “let’s write it together” and slowly writing the correct form beside them works better.

Do not compare with siblings or friends. Something like “your brother can already do it” may make the child dislike writing itself.

Mark where to start. I think mirror writing often begins with starting in the wrong place or setting off in the wrong direction. For a 3, start at the top left and go right. A small dot at the starting point gives a clear cue.

Copy first, then write from memory. If reversals happen more when writing without a model, it seems sensible to practise copying from a model first, and to move to writing without one once that is comfortable. A chart of numbers or letters on the wall, which the child can go and check by themselves, also helps.

Work on one character at a time. If several characters come out backwards, pick just one for today, say the 3. Trying to fix them all at once tires a child out.

Do not make them erase too much. Rather than having the child rub out a reversed letter and rewrite it again and again, I think it is enough if they write it the right way next time.

I wrote about the order for teaching numbers in How to Teach Kids to Write Numbers, and about when children start writing in When Do Kids Start Writing Letters?

What BrainDojo Kids does

BrainDojo Kids is an iPhone and iPad app for ages three to six. Its writing courses move through Trace, Copy and Write, and some courses, such as hiragana, finish with a short Test.

In Trace, the child follows the model one stroke at a time from the start of each stroke. In Copy, an animation draws the character stroke by stroke, and the child writes the same character in the box below. Where to start and which way to go are in view every time, so this is the “copy first” stage from this post. In Write, the child writes in a box with no lines to trace.

A written character counts as correct when it can be read as that character. The app has no feature that points out mirror writing. If the direction worries you, I think it helps if an adult looks at the screen with the child and checks it together.

Numbers are practised in the First Numbers course, and hiragana in First Hiragana. The first stages of each course are free, and the My Name course, where children practise writing their own name, is free throughout. For practice on paper, the Tracing sheets tool prints worksheets, and the first hiragana sheet is free.

In the parent settings there is a daily time limit, on by default at 10 minutes. There are no ads and no account to create. The app is free to start, and a Premium subscription (monthly or yearly) opens all courses and games.

Getting Started with BrainDojo Kids covers the first session, and Practical Tips for Using BrainDojo Kids Every Day has ideas for keeping it going.