The short answer, and you will not like it
No. There is no solid evidence that ambidextrous people are more intelligent than anyone else. In fact several large studies found the opposite — slightly worse performance among people who report having no dominant hand.
I know that is not the answer most articles on this topic give you. But it is the honest one, and it is more interesting than the comfortable version — because the reason those numbers come out that way is not remotely what it looks like.
Where the myth comes from
The myth has two parents, and neither is in good health.
The first is the genius anecdote. Leonardo da Vinci, Einstein, Benjamin Franklin — the same three names circulate forever. The trouble is that the list falls apart on inspection. Einstein was right-handed; photographs show him writing on blackboards with his right hand throughout his life, and the left-handed Einstein story is a straightforward urban legend. Franklin was almost certainly right-handed too — the belief traces back to a satirical essay he wrote in the voice of a neglected left hand, which later readers mistook for autobiography.
Leonardo is a more serious case, and I have written about him at length elsewhere. But even if every claim held up, it would remain an anecdote: "some brilliant people were ambidextrous" does not imply "being ambidextrous makes you brilliant". Those are wildly different sentences, and confusing them powers half the nonsense online.
The second parent is the two-hemispheres myth: the idea that the left brain houses logic and the right houses creativity, and that using both hands somehow synchronises them. It is a beautiful story. It is also false, and the research on this has been fairly brutal.
What the studies actually found
This is where it gets uncomfortable, so I would rather be direct about it.
In 2008 a team led by Michael Corballis collected hand preference and cognitive scores from 1,355 people through a nationwide televised intelligence test in New Zealand. Those who reported writing with either hand scored worse than both right-handers and left-handers, across arithmetic, memory and reasoning tasks[1].
It is not an isolated result. A large nationally representative study found that children with no preferred writing hand performed worse on nearly all developmental measures[2].
And as for left-handers — the other half of the myth — a systematic review with meta-analyses concluded that right-handers have negligibly higher IQ scores[3]. Negligibly. Meaning: the difference exists on paper and is far too small to mean anything for any individual person.
One detail changes everything here.
Those studies did not measure people who trained themselves toward ambidexterity. They measured people who ticked a box on a questionnaire saying they had no dominant hand.
These are two different populations. The second one also captures cases of atypical brain lateralisation, which in a small minority accompanies developmental difficulties — and it is probably that minority dragging the average down.
Translated: the data does not say training will make you less sharp. It says that "born without a dominant hand" and "learned to use the other hand well" are two things that should never have been put in the same group.
The myth of the brain split in two
Now the idea that refuses to die: the logical hemisphere and the creative hemisphere.
In 2013 a team at the University of Utah analysed resting-state brain scans from 1,011 people aged 7 to 29, measuring functional lateralisation across more than 7,000 brain regions[4]. They were looking for exactly this: left-dominant people and right-dominant people.
They did not find them.
Local specialisations absolutely exist — language, for instance, tends to be left-lateralised in most people. But there is no global profile by which an individual predominantly uses one hemisphere. Nobody is "right-brained". Nobody is "left-brained".
That local specialisation is the grain of truth that seeded the myth. Everything else was built on top of it. If you want the longer version with the proper nuance, I have written about creativity and logic in the brain hemispheres.
What training actually does
At this point the fair question is: if it does not make me smarter, what is it for?
It does what it actually does, and that is not nothing.
Training your non-dominant hand is motor learning, and motor learning produces real, measurable change. Practise a movement with one hand and the other improves without ever having tried it — an effect called intermanual transfer, documented for decades[5]. Your brain does not file the skill only in the arm that moved: a good part of it is stored abstractly, and both hands can draw on it.
What you cannot conclude is that this translates into higher general intelligence. Getting better at a motor task makes you better at that motor task and at related ones. Not at mathematics, not at memory, not at abstract reasoning.
Anyone promising otherwise is selling you something — and it is worth noting that I did in fact write a book about ambidexterity, so I would have every incentive to tell you a nicer story.
So why do it at all
Because the honest reasons are more than enough, and they do not need inflating.
- Pure curiosity. Discovering that a part of your body you ignored for thirty years is perfectly capable of learning is not an experience you forget.
- Practical resilience. Anyone who has broken their dominant wrist knows exactly what I mean.
- Sport and craft. From football to surgery, bilateral skill is a concrete, measurable advantage.
- Attention. Using the wrong hand forces you to slow down and be present in a movement you normally run on autopilot. It is not meditation, but it resembles it more than I expected.
None of those is "you will become smarter". All of them, in my view, are worth ten minutes a day anyway.
If you are curious where you stand right now, the ambidextrous test is the fastest way to find out — a couple of minutes, and a concrete baseline to measure against.
And tell me in the comments: did you fall for the two-hemispheres story too? I did, for years.
The truth first, then the method
I wrote this article because there are already plenty of pages promising you an upgraded brain, and another one was not needed.
Becoming ambidextrous is not a cognitive shortcut. It is a skill, and like every skill it is built with a method, gradually, with slow but real results. If the practical side interests you, I have collected it in how to become ambidextrous.
And in my book "How to Become Ambidextrous" I have put the whole path in order: a starting assessment, dozens of graded exercises for writing, drawing and coordination, and a day-by-day programme that also accounts for the stretches where nothing seems to be happening — which are the ones that decide whether you finish.
No magic promises. Just the route I wish I had found when I started.
Get it on Amazon and start with the method, not the promises!
- The relationship between hand preference, hand performance, and general cognitive ability (Corballis et al., 2008)
- Nature's experiment? Handedness and early childhood development (Demography)
- Right-handers have negligibly higher IQ scores than left-handers: Systematic review and meta-analyses
- An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging
- Specialization in interlimb transfer between dominant and non-dominant hand skills