SDSU Professor Writes Book On History Of Left-Handedness

Being on the left hand side of God means you could be thrown into the eternal fire. And a left-handed compliment is like an insult. These are two of many examples of how left-handedness has been held in disrepute across the ages. But, how did this dominant hand preference shared by such luminaries as Obama, Bill Gates and Oprah come a mark of infamy? Howard Kushner has been fascinated with this almost as long has he has been left-handed. Is a professor of history at San Diego State and author of the new book, On the Other Hand: Left Brain Right Brain Mental Disorder and History .Welcome to the show.Thank you.Do we know what causes people to have a dominant hand?No. People have been trying to answer this question since the beginning of recorded history. Once it was attributed to the devil. Other times it was attributed to racial inferiority. It has been associated with being female although there are less women left-handed than men and it has been associated with a number of earning disabilities -- autism, schizophrenia, dyslexia and stuttering. The question is whether the left-handedness is the cause or result of some of the conditions or whether there is any robust connection between them.What is the breakdown of left and right-handed people?It would depend on how you define it. It's also uncertain. Almost everything about left-handedness is uncertain -- the standard figure is 10%-12% with men being more frequent than women.Are there more or fewer left-handed people in one country?Yes, and that depends on the reports. For instance, in the West since the mid 20th century the numbers have been relatively high. This suggests no discrimination against being left-handed. In China where there is discrimination against being left-handed the Chinese report last and 1% being left-handed. When they move from China to the U.S. the rates are the same. There is a strong cultural and social constraint on what we can say about the numbers and the existence of left-handedness.How has left-handedness been thought of throughout history?Pretty much negative. As Seinfeld pointed out --You get put down for being left-handed -- left words are negative things. Leftovers -- it's terrible.Two (-- a left-handed compliment. Have you ever seen a crook named righty? [ Laughter ]Everything right is positive -- right on, the Bill of Rights.All the words for left-handedness in every language are negative. That has been around a long time. It's hard to say. Has there ever been a time when is positive? Yes. It's not exactly moving from negative to positive because, for instance, potato had a view of left-handedness -- -- plate oh.One author argues that left-handedness should be sicker because the right hand is what we kill with. It is up and down. There have been times when there was an attempt to see this more positively by certain groups. For instance, at the turn of the 19th century there was a movement called the ambidextrous cultural movement which encouraged people to use both hands. It was set up by the head of the Boy Scouts in Britain. In Britain the Boy Scouts shake and with the left hand.As I understand it, for some time it was thought that the right and left halves of the brain switched functions depending on the right handedness. Is that the case?Yes and no. Most of our motor functions are contralateral. My left hand is controlled in motor function by the right brain mainly. And the other way around for right-handers and left brain. The assumption was that when it came to language that it would be the same as it is. In other words, people would say -- especially people try to create a positive movement for left-handers -- that they are in their right brain. That is clever, but wrong.Only 18% of left-handers are qualified. 5% of right-handers are right brain. You think that there are 10 left-handers for every right-hander that means that there are more right brained right-handers and left brained left-handers.It is complicated.There are no easy answers. I thought this would be easy -- I thought I would write a funny book and that would be a.[LAUGHTER] it's not so easy. What has it been like for you being left-handed? Is a truly world designed for right-handed people?It probably is but it didn't affect me. I grew up with an advantage -- if you look at where left-handedness is accepted there's got to be an advantage. In my case it was baseball and sports. In China where they denied the existence of left-handedness, being a left-handed ping-pong player is a great advantage. Now they are encouraging this. So, the art of surprise in battle -- there is, in fact, some advantage to being left-handed. My mother was forcibly switched. As a result she became clumsier and she needed to be. She couldn't use scissors and it was difficult for her. I knew that going on. I wondered why that was.Let me get this straight -- you are saying that the idea that left-handers are more creative and more artistic is not the case?It's more like a U-curve. Many left-handed people have superior talents and skills. There are also many that don't do as well in testing. The question is, is this a result of encouragement and a left-handed movement or the result of something biological or genetic? It's not clear. Five of the last 10 presidents were left-handed.That's pretty interesting. Much more than you would expect. I got interested in this because I was working at a Tourette syndrome clinic. I noticed many patients with Tourette syndrome or ADD were left-handed more than expected. That's what got me interested in finding out about this. After 20 years I don't know the answer.In your book you say that acceptance of left-handedness can be a guide to a level of toleration in a society.Permissiveness -- societies that are constrained and force people to use the other hand sometimes you do this in violent ways. To humiliate them. They act that way toward all differences. First it seems like a trivial thing, it's not so trivial because it reflects our attitudes toward differences. If someone is left-handed there must be a reason. Generally if they are different must be negative. Societies that don't emphasize the difference seemed to be more open to other kinds of diversity as well.It is a canary for diversity.I've been speaking with Howard Kirschner, the author of On the Other Hand: Left Brain Right Brain Mental Disorder and History.Thank you.