Left-handedness and mirror writingFeatured science projectScience project video

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Complexity level:
Project cost ($):
Time required:
1 hour to prepare, 1 day for observation
Material availability:
Easily found. Ensure that your mirrors are not too large or small.
Safety concerns:

Handle mirrors with care to prevent injury


This science fair project was done to compare the ability of left-handed persons and right-handed persons in mirror writing. The experiment was done by comparing the time taken by left-handed and right-handed individuals to write some text in "mirror language".


Left-handers can mirror write more effectively and quickly than right-handers.


Left Handedness

A left-hander is a person who prefers to use his left-hand over his right to perform daily tasks. About 10% of the world's population consists of left-handed persons. Left handedness is a hereditary trait passed down from parents. There is usually more than one left-hander in the family. Left-handers usually have a parent, an uncle or an aunt who is also a left-hander.
Hand dominance may not be directly related to brain dominance. There are opposing views and a lack of substantiated scientific evidence on this.

It is believed by some scientists that left handed and right handed persons are controlled by their different sides of the brain. They believe that a right handed person is controlled by the left side of the brain whereas the left handed person is controlled by the right side of their brain, and that this happens because of the way that the nerves from our brains cross to opposite sides of our body at the neck region. However, hand dominance may not be directly related to brain dominance. There exist opposing views within the scientific community.

Mirror writing

Mirror writing is formed by writing in the opposite direction to what is considered normal writing in a given language. What is written in "mirror writing" is the exact mirror image of normal text. Mirror writing can be read through the reflection of a mirror.

There are usually more left-handed mirror writers than right-handed mirror writers probably because left-handers tend to have "language centers" in both halves of their brain. This causes them to read and write backwards quite comfortably.

Scientific Terms

Hereditary, brain, nerves


The materials required for the science fair project:

-    10 left-handed persons aged 15 years old
-    10 right-handed persons aged 15 years old
-    A text or phrase is chosen to test the participants
-    20 pieces of papers
-    20 pencils
-    A stopwatch
-    A mirror


1.    For this science fair project, the independent variable is whether the participant is left-handed or right-handed. The dependent variable is the participants’ ability (and speed) to write in mirror language. This is determined by using the stopwatch to measure the time taken for participants to finish writing the given text. The constants (control variables) are the age of the participants and the length of the text.

2.    Ten left-handed and another 10 right-handed participants age 15 were chosen to take part in this experiment.

3.    A simple text passage (eg. “This is mirror language” or “This is how I write in mirror language”) is selected. Any other simple text passages or sentences can also be chosen to test the participants.

4.    The participants are tested one person at a time. They are each given a piece of paper and a pencil. The participants are next given the selected text to be written in mirror writing. The stopwatch is activated and the time taken by the participant to complete writing the text in mirror language is recorded.

5.    The mirror-written text is checked by placing a mirror beside the text. The time taken to complete the mirror writing test is recorded in the table below.

6.    Procedures 4 and 5 are repeated on all 20 participants and results are recorded in the table below..


It is observed that the left-handed participants were quicker at writing in mirror language compared to the right-handed participants.

Condition Time taken to perform mirror writing (seconds) Average
  1 2 3 4 5 6 7 8 9 10
Left-hander 129 135 147 127 119 164 129 138 147 153 138.8
Right-hander 165 187 196 175 159 172 219 193 167 188 182.1

Use the below graph to plot the results of above observation.

 Mirror Writing Science Fair Project


The hypothesis that left handers will be able to perform mirror writing more quickly than right-handers is correct.

Mirror writing was once used as a form of cipher. In modern times, one of the most common forms of mirror writing is seen on the front of ambulances so that drivers in front of the ambulance can read the text in their rear view mirrors. Famous Italian inventor and painter Leonardo da Vinci was known to have kept most of his notes in mirror language.

Also consider

Repeat this science fair project by comparing the ability of ambidextrous persons to mirror-write.

Try to conduct another experiment with emphasis on gender and each gender’s ability to perform mirror writing.

Also, does age have any bearing on a person's ability to mirror-write? Are kids better than adults? Are adults better than retirees? How about the level of education of the participant? Does that have a bearing on your results?


Left handedness - http://en.wikipedia.org/wiki/Left-handedness

Mirror writing - http://en.wikipedia.org/wiki/Mirror_writing

Teaching left-handers to write - http://www.handedness.org/action/leftwrite.html