OK. I’m a leftie. Not only in politics, but in handedness. And, just like my politics are not all one-sided (fiscal conservative, policy liberal and then some), my handedness is even (ambidextrous). And, therein lies the rub.
You see, we know that being left-handed is associated with ADHD (Attention Deficit-Hyperactivity Disorder). Being ambidextrous renders you three times more likely to be ADHD than right-handed people. It also has been found to be a risk factor for lower mathematical skills, memory and reasoning- at least for children in Britain and New Zealand (but not in Germany- or for me 🙂 ). There also is association between mood disorders and schizophrenia with left-handed people. For example, 20% of all schizophrenics are lefties (even though they are only 10% of the population).
The estimates are that 10% of the world’s population is left-handed and 1% are ambidextrous. And, contrary to popular belief, being left-handed does not make you smarter. There may be a correlation with creativity (divergent thinking and the ability to conceptualize), but there is no difference in IQ between handedness. Nor is it true that lefties are more accident prone than righties. (Left-handed people do make 10% less than righties, though.)
Multiple births are more likely to result in left-handed children; one study of 30,161 adults (Drs. Vuoksimaa, Koskenvuoa, Rosea, and Kaprioa in Finland) found twins yielded 8.1% lefthanded children, triplets 7.1%, while single births had 5.8%. Males were more likely to be lefties than females. Ambidextrous children were more prevalent with triplets (6.4%) than twins (3.4%) or single births (3.5%).
This “altered state’ may be related to the hemisphericity of our brains. We know that right handed people have dominant left hemispheres, which is where language processing is based. 70% of the lefties also process language in their left hemispheres, even though their dominant hemisphere is right. But the 30% with a dominant right hemisphere (or have dominance distributed evenly between the hemispheres) that also process their language in the right hemisphere that may have these ‘altered states’. (Somers et. al, Utrecht, Frontiers in Human Neurosciences, 2011) It is known that schizophrenics tend to have symmetrical activity in their brain hemispheres, for example.
http://www.youtube.com/watch?v=9CEr2GfGilwBeing left or right handed is not really a function of genetics. At best, genes account for ¼ of the handed-ness tendencies. (For example, identical twins differ on handed-ness.) Studies by Obel found (Neuropsychologia) that stress in the womb is more likely to be the factor that determines handed-ness. In particular, mothers who experience familial death or job loss in the third trimester accounted for significant changes in handedness. In a study of 834 Danish mothers, the propensity for ambidextrous children was 17% for third trimester distress compared to 5%, without such stress. (The likely cause is cortisol, the stress hormone that also interferes with brain development in the fetus.)
By the way- that title- it’s taken from a coffee cup my kids gave me some 25 years ago..
If the video above confounds you, Peter Wasssink provided a key for you (and me) here.
This is the last post for 2011. I want to take this time to thank each of you for reading my posts this year, and to wish you a fantastic 2012.
If you are starting a business in 2012- or already running one- I would love for you to consider joining our program that will help you develop and use Key Performance Indicators (KPI), better goal setting, and grow your business to outstanding levels. Check out the program 2012 WILL BE GREAT
Interesting post Roy. Happy New Year : ) Thanks for all of your support this year.
Janine Ripper recently posted..Highlights from 2011
Glad you liked it, Janine….
Here’s hoping there’s some righties and lefties in your future…
Roy
Hi Roy,
Interested article. The statistics don’t match those that I know who are left handed, and I know a lot, so your post taught me new information.
Didn’t realize that being left handed indicated more ADHD either. My son has those issues and he is right handed.
But working in the world of phamaceutical and scientific studies, these types of statistics can vary.
Thanks for sharing this interesting topic and Happy New Year to you as well.
Cindy
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Statistics on left-handed people vary by country. But, from what I have seen, most of us think more of us are lefties than is really true.
I did not say or mean to imply that righties are not susceptible to ADHD; just that lefties (and ambis)- especially those who use their right brain for verbal processing (or both hemispheres) are most prone to that “altered state”.
Thanks for the comments.
Roy
My ambidextrous grandson keeps winning the math prizes at school and even though he has not yet completed high school, he has several university math courses under his belt. Interesting the study took place in NZ. What a load of….
I begin to wonder about the research in this country. It makes me want to scream!
Thanks for sharing Roy – oh and in today’s world where so many of us touch type – how does right and left handedness work anymore? We all are becoming more dextrous
Enjoy New Year’s Eve
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The research was fine- the results may be confounding.
And, last time I checked- lefties open different doors than do righties, we eat with different hands, we chew on different sides of the mouth (amazing, isn’t that?), we drive (since most only use 1 hand) with different hands, our mice are on different sides (less so), etc.
It’s not just touch typing- and how do YOU sign your credit slips??
HNY2U2,
Roy
You always hit such interesting topics Roy. As a teacher I always find it maddening to pigeon hole kids and I’ve actually had parents ask if there is anything they can do to ‘fix’ thier ambidextrous or lefty kids…really! They read some article or hear someone talk on the news and think it’s ‘bad’ but I wonder how much of these results are of a nurture issue than a nature issue? Obviously not all but I wonder if there isn’t a good bit of influence in some areas like maths or such.
Bonnie recently posted..So you want Peace on Earth do you?
Bonnie:
We all want our children to be “normal”; the problem is that often translates to average. I say- let’s relish the differences, since they help provide different viewpoints, so we can examine issues from all angles.
Roy
Very interesting! I’ve wondered what made the difference in right/left handed and hadn’t heard the cortisol connection.
Michelle Shaeffer recently posted..If Google+ or Publishing a Book is on Your 2012 Goals List…
I was amazed at that research, too, Michelle. I am looking forward to seeing amplification.
Roy
My sister-in-law (may she rest in peace) would have loved this post. My son is ADHD but right-handed. Interesting statistics, as always.
Twould that it be easy to determine exactly why ADHD appears, PeggyLee. Right now, the best we can do is help develop coping mechanisms.
Roy
Interesting information for those of us who have lefties in the family! Happy new year.
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Glad to oblige, Kristen…
Give my love to the leftie in the bunch…
Roy
Hey Roy,
A wonderfully informative way to end 2011!
Here’s hoping you have a beautiful 2012!
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To you, as well, Hajra- and to new ventures and opportunities…
Roy
When I was growing up, one of the sayings I remember my father using was “Figures can lie and liars can figure.” Statistics feel, to me, like stereotypes or limits or labels though I understand there is value in noticing trends and that our society seems to need numerical validation. I supposed, in the end, use them when they are a tool, not when they limit or attempt to define you. Great post with very intriguing observations…and I take statistics with a grain of salt. Statistically speaking, my late husband should not have succumbed to the form of cancer he had…but he did…so there are numbers and then there is what really happened in an individual situation…therefore…grain of salt.
Tambre Leighn/coaching by tambre recently posted..Here We Go Again…
Using statistics to determine one’s life or longevity only works if one is evaluating alternative treatments- which one may provide better results- and the verb is may. For one’s life- it is binary- yes or no. That would mean that we would expect every coin toss to alternate between heads and tails, since statistics says 50% of the time it will happen.
Not much comfort though, when it comes to the loss of a loved one, Tambre…
Roy
Very interesting information and stats you share here Roy. But I have to tell you that my brother is left handed and didn’t fall into any of the stats. But then again, there is always those exceptions. My husband was born left handed, but his mother and father taught him to write right handed. He played baseball left handed, which actually helped him to excel as he did. Thanks for sharing this information as I never knew there were so many things associated to left handers.
Lynn Brown recently posted..I Am Getting Ready for 2012 New Year, How About You?
I, too, wonder about these statistics, Lynn. As the only lefty (ambidextrous) in my family, one would consider only I would be subject to these conditions. NOT!
Roy
Wow! Other than the correlation between lefties and creativity, these are all facts that I had never heard about before! Captivating post, Roy! =)
Happy New Year, btw! =)
Samantha Bangayan recently posted..Home Is Where the Heart Is in Peru and Canada
Glad you enjoyed the post, Samantha…
Happy new year to you, as well…
Roy
Very interesting approach – cortisol influences our brain and thus our hand-usage? I didn’t know that. And what determined the level of cortisol?
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Anna-
The researchers reached these results from retrospective studies. The next effort is to determine how much cortisol release is involved with this switch.
Roy