Anything Left-Handed > Research > Left handed research

Research Into Left-Handedness And Its Effects

See our page of current lefty research and results

There has been a huge amount of research done into various aspects of left-handedness, often without much in the way of clear conclusions. We will be using this section to provide articles and links for you to see and to let you know of current research that is going on that you could possibly participate in.

If you are involved in research into left-handedness or its effects, please let us know and we will include details in this section.

We have a lot more information to go in this section, so check it again next time you visit us.

New age of genius led by left-handers! (Mar 2002)

Evolution may be in the process of delivering a new age of genius and creativity, with left-handers leading the way. Professor Chris McManus of University College, London has been researching the subject and is about to publish a new book called Right Hand, Left Hand. He is convinced that the proportion of left-handers is rising and left-handed people as a group have historically produced an above-average quota of high achievers.

He says that left-handers’ brains are structured differently in a way that widens their range of abilities and the genes that determine left-handedness also govern development of the language centres of the brain.

In Britain, around 13% of men and 11% of women are now left-handed, compared to just 3% of those born before 1910. There are a number of factors driving this increase:

  • Left-handers were severely discriminated against during the 18th and 19th centuries and it was often “beaten out” of people
  • In adulthood, left-handers were often shunned by society, resulting in fewer marrying and reproducing
  • As discrimination was reduced in the 20th century, the number of natural left-handers who stayed left-handed increased
  • The rising age of motherhood contributed as, statistically, older mothers are more likely to give birth to left-handed children

The professor says that the increase could produce a corresponding intellectual advance and a leap in the number of mathematical, sporting or artistic geniuses.

Unfortunately, it is not all good news for left-handers. They tend to be over-represented at both ends of the intellectual scale and as well as geniuses the group also produces a disproportionately high number of those with learning handicaps. There have been suggestions of links between left-handedness and dyslexia, stuttering and child autism among others.

Left-Handers Club comment…

We have had a lot of anecdotal evidence of an increasing proportion of left-handers among young children and our correspondence with members supports the view that left-handers are over-represented at both the top and bottom of the learning and achievement scale.

Now that left-handedness is not actively discouraged and young left-handers can obtain basic tools like pens and scissors to allow them to learn and express themselves in their own direction, most stay as left-handers and do not have their naturally creative advantages interfered with.

We have known Professor McManus and his work for the past 10 years or so and we will give further comment on his current project when the results are published in full. We also hope that he will give us some further background and personal comments that we can pass on to our members.

The Left-Handers Club is planning a major series of surveys this year which will aim to discover which activities and occupations groups left-handers are over- and under-represented in and the factors that affect this. We will be producing further information on this and asking for assistance very soon.

Ambidextrous tendencies may mean better memory

Source: New Scientist, 22 October 2001, James Randerson

Having a close left-handed relative makes right-handers better at remembering events than those from exclusively right-handed families, new research suggests. There is a downside, however, as members of these ambidextrous families may be relatively impaired in their ability to recall facts.

According to the study, having a left-handed sibling or parent means the organisation of your brain is intermediate between a pure ‘lefty’ and a pure ‘righty’.

Specifically, Stephen Christman and Ruth Propper at the University of Toledo, Ohio claim that people with ‘lefties’ in the family have a larger corpus callosum – the connection between the brain hemispheres. This makes you better at certain memory tasks, but worse at others, they believe.

Two types of memories are involved. Episodic memories are those with a context that is separate from the information itself – for example, where you parked your car or where you left your keys. Semantic memories on the other hand are things ‘you just know’, such as the dates of the First World War or the recipe for apple pie.

Filling the gaps

The researchers showed 180 right-handed subjects lists of words. Some of this group was asked to recall as many of the words as possible once the list had been taken away. This tests episodic memory because the subjects have to remember the words they were taught.

Others from the group were given fragments of words with a letter missing and asked to fill in the gaps. This semantic test simply relies on knowing how the correct word should be spelt. Subjects with close left-handed relatives did better at the first ‘remember’ task, but worse at the second ‘know’ task.

“The key difference is not whether you are right handed, but whether you are strongly or weakly handed,” explains Christman.

Making the connection

A definitive explanation for the results is still some way off, says Christman. But he suspects that it might involve the roles that different brain hemispheres play in memory. He believes the information itself tends to be stored in the left hemisphere, while the place and time context resides in the right.

Both these components will be useful in episodic memories, so he suspects that people with a large corpus callosum linking their hemispheres – such as those from more ambidextrous families – will do better at these tasks. Semantic memory requires only one hemisphere, so it may be that those with fewer connections between the hemispheres have less interference and perform better.

Chris McManus, an expert in handedness at University College London, agrees that people with left-handed relatives have a brain that is “slightly more like that of a left-hander”.

But he is sceptical about Christman’s explanation. The link between a weak-handedness and a large corpus callosum is “distinctly controversial”, he says.

Journal reference: Neuropsychology (vol 15 (4)

Ambidextrous: The worst of both worlds?

Leading British psychiatrist Prof. Tim Crow believes he can show that ambidextrous children are less intelligent than their peers – and his theory could even shed light on schizophrenia.

Unlike our closest genetic relative the chimp – who is truly ambidextrous – humans tend to heavily favour one hand and struggle to perform simple tasks with the less favoured. Prof. Crow, of the University Oxford, believes this difference could be crucial to the evolution of humankind around 137,000 years ago. The development of a division in function between the left and right sides of the brain – which result in our tendency to be right or left-handed – was a major factor in our leap from Homo erectus to Homo sapiens.

“Handedness is the key dimension of human cerebral function,” says crow. “People who are truly ambidextrous are slower to develop verbal and non-verbal skills. It’s the predictor of both reading difficulties at the age of 16 and psychosis”.

For his study, Crow analysed data taken from 12,770 1 year old children taken in 1969 as part of the UK National Child Development Study. The children had been tested for hand preference, verbal, reading and mathematical ability. The test immediately resolved the age-old argument over whether right or left-handers are more intelligent : the answer is that there is absolutely no difference between them. What was startling was how badly ambidextrous people performed in the study – they did dramatically worse in all 3 tests. Youngsters who were extremely right or left-handed also tended to do poorly, but not as badly as the ambidextrous children.

“There seems to be an optimum level of handedness at which we perform best, although we are not sure what that is” said Crow. “Most of the variation in intelligence is to do with the degree of handedness in the child.”

Crow is aware these results may anger the parents of ambidextrous children, but he stresses that more research is needed to interpret the results fully. “The problem is that intelligence is a nebulous concept” he says. “These children may simply be late developers. Or they may be developing in a completely different way.”

Crow says that the gene responsible for encouraging specialist functions in one side of the brain, such as handedness, is what allows us to develop advanced skills, and without it the language centre of the brain would not have been able to develop. It is this development of language that differentiates us from the animals, and Crow’s research continues into pinpointing exactly which gene or group of genes this is.

The consequences of this could be controversial, since they raise the possibility that we may one day be able to manipulate the very genetic material which makes us human. However, although this gene may set us apart from the apes there appears to be a cost. Crow believes that the same genetic changes that allowed the development of language by creating imbalance in the brain also created the potential for schizophrenia. “It is the price that Homo sapiens pay for language” he says.

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77 comments on “Left handed research
  1. Andrew Jackson says:

    So many studies that are conducted in the area of lefthand dominance, with the specific goal to find the origins of what causes a person to be left-handed.
    I am not advocating against these studies but there needs to be research into the effects of left-handed children forced to abandon their natural hand dominance.
    The abuses of children over the subject of hand preference needs to stop.
    Child abuse is not tolerated for any reason except in this one area and in this area unlike most there is little means for escape.

  2. Sarvesh says:

    Hi guys, I am left handed. However, I can use both hands efficiently but I prefer using my left hand more. For example, I can eat with spoon using my left and right, but more quickly with left than right, can write with both hands but prefer left and is considerably slow with right. While playing cricket, I bowl with left and bat with right.

    When I read comments here, I realized I share a lot of similarities with many people and felt really happy that I was not alone sailing in rough sea. For example, having two solutions to simple problems and then struggling to decide which one is the correct. I am 24 now, but I still face it. So, I started training myself to think how other’s think so that my answers match to theirs and I am still working on that part.

    But, the most difficult thing that I face is understanding/relating oral instructions like (being part of some rapid conversations, giving directions to someone ) and another is imaginary counting. Like, suppose I have to add two four digits numbers, I take time to imagine them and then while generating results even at the units place, I again lose track of the number, re-imagine and perform the task. It takes a long time and affects my speed. SO, the only work around I have for it is, I write down the number and perform it.

    I would like to know if anyone is facing a similar problem?, is it specific to Lefties?, is it some kind of disease and can I overcome it with practice of certain things?. Like, I have tried to solve many problems mentally, but no much useful effect I have seen.

    Someone please reply.
    Thanks and have a nice day.

  3. Mrs Carol Costello says:

    Hello. Iam a 71 year old lady. I had always been left handed, plus done sports or tasks ,such as neddle work, knitting music, left handed. But over the last few years I have started to do nearly everthing with my right hand except write,& sew. I find this very very strange.
    Have you found other people have had this happen.

    Really would like to know.
    Your’s Sincerly
    Mrs Carol Costello

  4. Corene courtnage says:

    I’m left handed and I work as a midwife. I am astounded by how many of my colleagues are also left handed and wondered if this trait may be linked to a predisposition have careers in healthcare? I have a twin who is right, but my mum is left and she was a healthcare worker for years.

  5. James. C Harrison says:

    My parents at an early age of me being born forced me to use my right hand and now at the age of 47 my left hand and arm have pain. What was going on in 1969 that had people so afraid of left-handedness?
    What was special about US?

  6. Sadie Hill says:

    I found this article as I am trying to find answers for my son. Long story short, or I’ll try. All through grade school I literally had to sit in class with him as I refused to shove pills down his throat or allow them to follow through with threats of calling a psych ward and having my child locked away. I am not exaggerating, I wish I were. The school authorities (more than one) told me he was basically retarded and he would never be able to function in society. Fast forward to him in high school. He has held a job since the age of 16, graduated and is currently in college. He has trouble passing classes but his behavior has gone from and F- to an outstanding A+. He’s “different” to say the least. You can’t tell by looking or even on first or 30th interaction but after a while you will see *it. I’m not sure what *it is, thus I am here, randomly commenting, desperate for answers. When he was young he would switch hands when one hand got tired. He never made eye contact until around 18yrs old(I told him tirelessly he had to). At jobs his supervisors are in awe at his ability to complete a task (any task) with 100% precision and always 110% above quota goals. No matter the task, he surpasses everyone. I hope I find somewhere to can help study his mind. Not in a weird lab rat kind of way but then again, exactly in such a way. I’m not sure if he is autistic or savant. I am not just a love blind mom in this. I have been told too many times that he solves equations, problems, completes tasks at an oddly good rate. I know once I can get him to pass his college classes he will be amazing, and he understands he needs the document to get in the door. I am super sorry for writing such a long comment but I feel you may be able to lead me in the proper direction.
    Thank you

  7. Dirk van Schalkwyk says:

    I am a teacher in a primary school teaching Gr7 learners. During an outreach in July 2016 I made surprised observation: Amongst 40 children at a village called Machaila in the centre of Mozambique about 20 out of the 40 children were lefthanded. I’m going back there in July 2017 and would like to research the lefthandedness in this village/area. I have no expeperience in research of this nature and would appreciate any help or ideas how to approach this kind of research.

  8. Dylan says:

    Im ambidextrous but very intelligent. I was helping my brother do his Grade 9 Math homework when i was in Grade 4. He got 94%. I first figured out i was ambi when kids dared me to write my book report with my left hand when I was in Grade 4. Since then, I’ve favoured the left hand. (I have an ambi dad and a left mom.)

  9. Hal Barbera says:

    I was born right-handed, but have trained myself to be able to write easily with either hand using up to 16+ hand-pen positions.

    It was difficult at first, but is now second-handed.

    I’m retired and into neuroplasticity and neurobics.

  10. Mandy says:

    I just took a class of trainee music teachers at university. I watched as they completed writing responses to a listening task. Of the thirteen students in the room, seven were left-handed. At one table, four of the five students were left-handed.
    In the same class last year with a smaller number of students, half were left-handed.
    The left-handed students today were really happy to be in the majority!
    I’ve been reading about links to the vestibular system (really important in music) and the corpus callosum (above). Male musicians tend to have larger corpus callosums than the rest of the population. Females just have relatively larger corpus callosums in proportion to the rest of the brain. Not different in female musicians. So I’m fascinated by the research into left-handedness. Thank you!

  11. Sara says:

    Growing up as a left-handed child, I was always a little bit quirky. I’ve always been clumsy, however very book-smart and have never gotten a bad grade in my life (Maybe because I have a photographic memory…yay lefty quirks!). When I was little my mother didn’t make the connection between her five-year-old coloring with their left hand and me being left-handed, so for the first few years of my life I was sort of right-handed, although once she told me I was coloring “wrong” I sort of grew a distaste for the subject altogether. Thank God for my second-grade teacher (I skipped a grade) figuring out I was a lefty.
    Now, I’m almost sixteen, and I’ve become a sort-of famous Instagram artist, and I couldn’t be happier that I made the choice to embrace all of my little lefty quirks.
    My little sister is left-handed as well (which is weird since neither of my parents is) and I hope that she learns to embrace all the little oddities that come with dominantly using her left hand.
    Maybe one day.

  12. Paul Baxter says:

    ust be glad to be different than the other 90% of the population. I was lucky I was so dominantly Left handed that in the 50’s my mother and a local doctor made sure I stayed that way(thank goodness) Their is a left-hander in each of my siblings families and one sister has 3 children and all are left handed. I had a grand parent on each side that was left handed. I have Aspergers (Higher functioning Autism) and ADHD. But who cares as long as you are happy with what the creator has handed you. I have a natural affinity with anything to do with maths as has all of my family on both sides. I have bad short-term but amazing long term Memory. They are just now finding out about the correlation between left handedness and other brain dis-functions, I noted this at least 20 to 25 years ago. I love any thing to do with learning but have always tried to look past the pieces in any learning that have no use in the final outcome, eg in learning about how to fix computers they try to teach you how each piece of hardware works and functions which mostly have no outcome on diagnosing and fixing the hardware of a computer. Knowing the mathematical functions of a CPU is only needed if you intend to work in the sphere of engineering new CPU’s. I do not know if it is how my brain works that looks past the superfluous to get to whats important to me I just do it. I like to describe the way my brain works. My brain works on the linux system and to think as a so called normal (right handed people do) I have to run a windows system on top of this linux system. Well good luck to all of my fellow Lefties out there as I said just be glad of who you are we are only 10% but maybe the best 10%, and maybe the 10% that will save the other 90%.

  13. Samuel says:

    I was changed from left handed since 5yrs old. Now am 25yrs..
    But now i still find it difficult to grab things easily . I quickly forget things.
    Anyway out pls.. Looking forward to your responce tru my email address. Thanks…

  14. Aisha Ahmed says:

    Hi,my 3yr old preferred to use her left hand b4 she started school. I noticed she writes with her right now and she told me when I asked that her teacher tells her to write with her write. It’s taking her a long time to learn how to write and when she tries to write some nos with her left now she writes it funny. Although she still prefers to pick up things and use utensils with her left. I’m a bit worried

  15. Alex B says:

    Me And Bro left handed: both at least above avg intelligence.

    Sister: Right handed, above average intelligence, but not as smart as my Bro or I.

    Mother: Ambidextrous, not very smart in comparison, average intelligence if not below.

    How do we not know those from earlier history who were forced into rightyness, didnt cause mental and emotional conflict, including learning obedience, and getting reinforced for listening to authority?

    Geniuses are those that go against authority in one way or another. By definition geniuses are people that actually think “more”, average people just believe they think, or don’t think at all.

    Average are those by its own definition, follows the crowd, these people arent world changers.

    Think about it.

    I could go on and intertwine 10s of ideas, facts and theories, but I’ll resist.

    Lefties are only smarter because we’re always against the tide, cant create new without conflict, just like cant study a species without changing them.

  16. Julie says:

    I write with my left hand and do everything else either right or left. I have been referred to as either awkward or clumsy. I have always been extremely book smart. I often times answer verbally the opposite of what I am thinking. If I want to say up, I often say down. I have always blamed it on my mixed hand dominance. It can be a struggle sometimes

  17. Cristina says:

    I am not left handed, however my brother is. I would like to know a little more about how being left handed(thus using the right side of your brain to direct your dominat hand) affects or if at all your math skills. I’ve been reading on Broca and Wericke and am wondering since in their theories math is on the left side of the brain, it could be that my left-handed brother has trouble with math. Help or insight on how to help this would be greatly appreciated…

  18. MAnuel George says:

    My experience in a right handed school system was not good at all. Its a place where lefties do not fit at all yes some of us can make it through and do well. The thing in right handed school system one has to learn but not understand something like a piano player that can only play music from a music sheet. Take the music sheet away and the music stops lefties hardly learn like that. We learn to understand why then play buy ear. A lefty can see two things at once I will give an example if i draw a box the box can change shape on the paper to produce different views of the box. Righties have a hard time to produce this feat so left handed people in schools will come up with two answers one the righties can understand and the other that lefties can understand so when lefties answers in class they have a dilemma which answer is the right answer, they have to choose and if they choose the right wrong answer, yes you read that right say it again the right wrong answer according the to the righties perspective then the leftie is consided dumb. Imagine what that does to a person you begin to doubt yourself and consider yourself dumber than the other pupils. Its only when one makes it to university or collage is one required to have divergent thinking that should be taught in primary school for lefties and we do not mature later we were never given the the chance to mature at all.

  19. kerry says:

    my 10 yr old daughter writes english etc with her right hand and writes her maths with her left hand. School thinks she’s dyslexic i wonder if she’s swapped hands at some point because mostly everything she does is with her left, anyone else do this?

  20. Emily Ferguson says:

    My name is Emily Ferguson. I am left handed and I have always been at the top of my class in maths and art. I am now studying social care at college and have passed every exam first time. I am the only left handed student in my class and everybody comments on how lovely my writing and art work is. I do not know if this is because i am left handed but a lot of people seem to think so. My mum, dad and sister are right handed and my mum was very young when i was born, although my cousin, gran and grandad and auntie are left handed and my auntie went to art school and my gran and grandad are great at maths. Is this because the are left handed? I do not know but i would love to find out.

  21. Mitali says:

    i’m a final year u.g physiotherapy student and i am currently searching for a project regarding the difference in kinematics of right handed v/s left handed population or the relation b/w being a lefty and having problem with some instruments.
    can someone help me in finding refrences for either?

  22. Alice* says:

    “The researchers showed 180 right-handed subjects lists of words. Some of this group was asked to recall as many of the words as possible once the list had been taken away. This tests episodic memory because the subjects have to remember the words they were taught. Others from the group were given fragments of words with a letter missing and asked to fill in the gaps. This semantic test simply relies on knowing how the correct word should be spelt. Subjects with close left-handed relatives did better at the first ‘remember’ task, but worse at the second ‘know’ task.”

    I’m a southpaw, and I’m not good at remembering. I’m better at knowing.

  23. Connie Fornash-Burrows says:

    My own struggles to determine which hand to use for different tasks (ex. write left-handed, almost all else right-handed, mouse the computer w/both hands, etc.) have led me to wonder if there are many of us out there for whom a dominant hand did not emerge. Are there studies about such issues? I would be very interested to learn of others who had to choose, and may have had to revise, which hand to use.
    Thank you!

    • sarah says:


      I am also left handed. I use my left hand to write, and I eat with my right hand. I never knew being left handed means you are more intelligent but this will give me huge self esteem from now on.

      I am really bad at aiming, can’t use any of my hands in it successfully. Sometimes I throw with my left some times my right, undetermined.

      I forget a lot. I have a very selective memory. This is hard for someone who works in the academia.

      I respond to verbal conversations really slowly. It can take days to find the right answer to a conversation.

      • sarah says:

        I forgot to mention that my 3 year old daughter is also left handed.
        I usually catch myself jumping from topic to topic in a conversation. People don’t understand me. I believe I was pushed very hard to think like a right handed person. Although my mom never criticized me for being left handed, I hated school and learning from a very young age although my grades were excellent. When I went to college, I scored high in some classes and very low in others. Classes like architecture and engineering drawing were my favorite. But stuff that required memorizing were very hard for me. I liked any creative or artistic class.

        Now I am doing my Masters in computer science. I am still able to mimic right handed way of thinking, I can memorize I can write ugly proofs but am I happy with what I’m doing ? No. My advisor in my grad studies does not understand me. He thinks I am not focused enough. *** this. I just can’t keep up with the stuff you’re saying. I do a lot of good work but unable to present it to him in a way that he understands. I am not arrogant or saying I’m smart, I just can’t communicate with people. It’s hard, any suggestions my fellow lefties??

        • Paul Baxter says:

          I have to say I sympathize with you in all you say about communication, I have ADHD on top of my left handedness and my brain thinks so fast I sometimes start my conversation so far along it that my sibling and friends actually help me by telling me about this, and I to jump from conversation to conversation as my brain thinks so fast. In writing up any sort of dissertation that I need for something in academia, I have trouble explaining it in writing I can explain in conversation no trouble. I find myself going to lots of articles written by others and trying to make a comprehensible paper that is 90% my own work. I do not know if any of this will help but just reading this. What you have written helps me to understand that their are others out there that struggle. Sarah I am 65 and still trying to make sense of my world and still hope to do a degree in child Psychology starting in 2016 and hope to finish when I am much older.

  24. Josh says:

    Of the top 4 students in my school (GPA wise), 3 of them are left handed, myself being one of them. The other two are also both my best friends, but I didn’t even know they were left handed until after we had become friends. Very weird how that happens.