Episode Transcript
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Speaker 1 (00:03):
Welcome to Stuff to Blow your Mind from how Stuff
Works dot com. Hey, welcome to Stuff to Blow your Mind.
My name is Robert lamb Man. I'm Julie Righty Douglas.
That's right. I'm right handed as well. This is a
right handed podcast. Now, technically Noel, who records this is
(00:23):
left handed, but this is a right handed podcast, so
we forced him to use his only his right hand
and left is down behind him at all times, at
least when he's recording us. I don't care what that
other podcasts do, but darnet, we have standards here. We do. Yeah,
we're keeping it right and tight all the time. Yeah,
because what we're firm believers that left handed individuals are debased,
(00:44):
their evil to freaks of nature, and they should be
distrusted at least and re educated along the right path
whenever possible. I mean, that's why we have the rule
of left hand behind the back in the podcast booth.
I mean, my wife is was born left handed. She's
right handed now because we have that corrected, and and
I love her, but I love her because you know,
(01:05):
we corrected what was wrong with it. Yeah. Well, you
know my husband is left handed, and uh, every once
in a while, I will catch him using it. And
our daughter's ambidextrous, and that's frowned upond as well. Yeah,
well but that can be that can be fixed over time.
We're trying, we're trying to firm with the discipline on
everybody in your life that is tempted to use their
left hand for for anything important. Yeah, so keep that
(01:26):
in mind as you guys are listening, whether or not
you're a righty or a lefty. Yes, it can be corrected. Now.
Of course, we're having a little fun here with with
our lefties, because of course there are all sorts of
stories about the left. Left handedness signifies evil, and left
handedness is wrong. And certainly we have created a right
handed world because the vast majority of individuals are right handed.
(01:47):
Only ten percent of the population is actually left handed.
And and and in reality, there's nothing evil about you guys.
But I love poking fun because everyone knows that this
is not true. But but when you when you start
prodding and poking the left andy's about this, they sometimes
get a little up in arms. Well it's true, because
I mean, think about it, you're pretty much outnumbered everybody
else using it right hand you're forced to use the
(02:10):
scissors that are awkward and bunched up, and all sorts
of different ways that you're navigating the world in which
you have to try to fit in to this right
hand world. Yeah. But but as we'll discuss in this episode,
left handedness brings with it its share of benefits in
addition to its many curses. Now, you guys might have
the upper advantage. Actually, yeah, certainly literally the upper hand,
(02:35):
the upper left hand advantage. Um. So, by the way,
I wanted to point out that you guys have been
ten percent of the population for a really, really long time.
And this is according to Perry Class, writing for the
New York Times, the size of the South Paw population
has held constant ever since hunter gatherer days. And this
is data that comes from studies of cave paintings and
(02:58):
archaeological analysis of ancient artifacts and how they were used.
So we know that for what at least ten fifteen
thousand years at the very least, that this has been
going on. Of course, you know, the human species extents
well beyond that. But right now we know you guys
have been the minority for a while. Now. It is interesting,
and we'll discuss the reason for this shortly, in some
(03:20):
areas where it's particularly a war torn where there's a
lot of violence going on, you'll sometimes see that the
number of left handed individuals increase. And this is this
is due not to the fact that left hand needs
are evil and then if there are more in an area,
it makes that area more prone to violence. But it
comes down to having a left handed advantage, supposedly in combat,
(03:42):
and we'll talk about that. We'll talk about why being
left handed is actually an advantage um not just in
in uh cognition, but also in warfare and other sports.
According to a two thousand and eight study, a meta
analysis of one forty four studies, that's a lot which
included one point so than million people. It's a lot
of people. To men have one point two three times
(04:05):
the odds of being left handed compared to win the chances.
So if you are a lefty woman and you're super
in the minority, which is weird because it seems like
I'm around a lot of left handed ladies, Like my
wife is left handed, my sister is left handed, and
we have at least a couple of lefty ladies here
in the office. It's true, you should probably examine. I'm
(04:26):
not going to out them, really, I don't know to
what extent there. Well, I think they're proud, Are they proudly? Yeah,
lefties tend to be proud these days. And then well
they should be Alison labor Milk, Christine Conder. Yeah, it's
not gonna be like they can hide it because you're
inevitably gonna have to go to a dinner and you're
gonna be bumping elbows with the right. Yeah, that's my
chief complaint. I have to say with my husband, we
always have to make sure we're in the right position
(04:48):
eating dinner position, that's right. See, mother's over forty are
one percent more likely to give birth to a lefty
than younger mom in their twenties, and only about one
percent of the population is truly ambidextrous. And this is
according to Live Sciences article south Paw Stats. Now, when
(05:08):
they say truly ambidextrous, what we're talking about here is
that there's a kind of spectrum of handedness, and so
people may be a little bit left handed or very
left handed on the spectrum, and it kind of reminds
me of the Kinsey Scale of sexuality. People heavily identify
as homosexual orsexual. There's a lot of room in between.
(05:32):
There's a sliding scale, and you're not necessarily going to
be one extreme or the other, but somewhere on that scale.
And the same host for left handedness and and the
and uh and behmbidextrous. That's true. All right, Let's talk
about genetics, because lefties, I feel like are often given
really short shrift in this area because there's an association
of increased cases of schizophrenia a d D and dyslexia
(05:54):
with left handedness. Yeah, and a lot of this comes
down to l r r t M one. That's the
specific gaine that's passed on from the father that tends
to increase the chances of someone being left handed, and
the same gene seems to confer slightly increased chance of
schizophrenia slightly slightly. Yeah. And by the way, this was
a study on dyslexic children, so I thought that was
kind of interesting. They weren't necessarily going after and trying
(06:16):
to figure out an association with it. It wasn't funded
by the by the the lefty support organizations or the
or the righty power organizations. That's right, wasn't funded by
the right. Um, So you have something called dextral or
chance genes. And according to Claire poor Act she's a
professor of psychology at Penn State Theory, humans are born
(06:38):
with two genes for handedness. So you either have dexterral
or chance, and the dominant dextral gene induces right handedness
whenever it turns up. But if there are two pairs
of chance genes, then that is when you become more
prone to becoming a lefty. Now, all of this being said,
there is an environmental factor here as well, so it's
not just coming down to janea um. Consider that identical
(07:02):
twins often have dominant hands, and this is according to
a Violin Lorens and evolutionary biologists. So even twins could
be differently handed, which makes sense because one can be
like the reflection of the other, right ones, the evil
twin once the good twins exact. Right, Well, I'm wonder
which one is the evil one? Now this is interesting, uh,
and this one we can just getting out of the
(07:22):
schizophrenic area and into some of the positives. Lefties, they say,
tend to have a more balanced view of their bodies,
and that's because when asked to the angel visualized space.
A righty tends to be more sensitive to their right side,
uh and their left side is more like a like
a t rex little arm, you know, so like imagine,
you know, we've all seen the homunculous, not the real
homunculous that a wizard bruise up, but the one that
(07:45):
represents our body image in our sense organs and and
and basically the shape of our body as as internalized
and sense. Like if we were to look at the
way a righty views their body, it would be, you know,
a very right hand dominated like a giant right right
arm and then like a tiny left arm, like they're
(08:06):
very very lopsided, whereas a lefty tends to uh not
have that kind of bias. And this comes from a
lifetime of having to deal with all the right handed
stuff in our world. So they're having to deal with
all of this right handed stuff, but they're actually left handed,
so the to kind of cancel each other out and
right the ship right, and which makes it makes sense
(08:26):
that there's more spatial awareness and could possibly be one
of the reasons why a lot of lefties tend to
be engineers, because there are people who can deal with
spatial reasoning really really well. Um, and a lot of
this has to do not just with spacial reasoning, but
just your processing your motor skills, also language processing. But
(08:47):
going back to motor skills, just wanted to lay out
there that the nerves connect our hands to the areas
of the brain responsible for motor skills. So there's a
separate set for each hand, but the wiring is crossed,
so you're right hand is hooked up to the left
side of the brain and vice versa. But when you
look at left east, they're taking in data and they're
(09:07):
they're really bi cerebral if you think about it, because
they are factoring in particularly language in both hemispheres, whereas
right eas are processing language in the left hemisphere. So
as a result of the corpus close and we've talked
about this this little guy before, it's a part of
that connects to both hemispheres. Is about eleven larger and
(09:27):
left handed brains than right handed brains. And this is
this idea that it's actually aiding the left east to
be quicker on the uptake of information and processing it.
All Right, we're gonna take a break and when we
come back, we're gonna deal more with left handed individuals
about why you might want to think twice about getting
into it. It's fight with one all right, we're back.
(09:59):
We're talking about lefties. And if you engaged in sports
or fist fights, or sports and fist fights or fist
fights that are actually a form of sports, there's a
chance you're gonna come up against the lefty at some point.
They're only ten of the population. But when you start
looking at some of the big names in sports, you
look at Adam Palmer, you look at Bobby Or, you
look at John McEnroe, Oscar de la Hoya, and Babe Ruth.
(10:23):
Even though Babe Ruth supposedly wrote right handed, these were
all lefties. These were all people at the top of
their sport and they were doing it with the left hand. Yeah.
And as you had mentioned that lefties living in the
right hand world, they have much more spatial awareness on
both sides. Right And according to Melissa Rough in her
(10:43):
book The Left Stuff, bio mechanical research has revealed that
training the non dominant side of the body can actually
enhance the dominant side, and this is known as the
cross training effect, and the body's neural network is integrated
on both sides, which would confer an advantage already, right, right,
And then if you're you're training to do from you know,
to combat other individuals, say with swords, with with pointed sticks,
(11:06):
or in engaging to to fight against some in a
boxing match or in tennis, you're going to more likely
you're gonna train mostly to deal with the population, unless
you're you're saying I'm only going to box schizophrenics, in
which case you're gonna deal with of that population is
left handed. Actually due to the slightly higher chances that
we talked about earlier population of lefties. Yes, yes, yeah,
(11:31):
so most of your training is going to revolve around
fighting other rightings or even if you're a lefty, you're
going to be more predisposed to fight right eas But
then when you deal with a lefty, it's going to
potentially skew things just a little bit because their hand
dominance is gonna be gonna be different, uh there, and
their training is going to be different. It throws things
(11:52):
out of whack. And we see this in the natural
world too, right. We see this with sea snails that
actually the shape of their shell are coiled counter clockwise
or left as opposed to the more typical clockwise arrangement.
Now why is this useful, Well, it's because right claude
predator crabs are used to kind of can opening them
(12:13):
right with their with their claws, but they come upon
a sea snail who's a lefty with a counterclockwise swirl
or configuration to their shell and they can't get in
there and crack them open. Yeah, they have evolved to
eat right e's and then when a lefty presents itself,
they can't cope with it. They have their their form
is not suitable to this altered form. Would like a
(12:36):
righty in in the um the boxing match with the
lefty right exactly can't really anticipate how this is going
to play out. Yeah, now that's that's why a boxer
knows that he or she is going up against a lefty,
then they'll intensify their training, uh with a with a
left handed sparring partner, because because again the percentage is there.
You can't go if you're a professional boxer, if you're
(12:57):
a professional tennis player, if you're just they do with
a sword in a on a medieval battlefield, chances are
you're going to encounter that left handed individual at some point,
and you don't want to just be completely decimated by
then when it happens. But even that, even the training
is not going to give you the advantage that lefties
have with the processing right. With the cognitive processing, study
(13:19):
leader Dr Nick Turban from the Australian National University took
left handed and right handed people and recorded the transfer
time between the two sides of the brain. And he
did this through measuring reaction times, and reaction times being
huge in sports. UH two white dots flashed to the
left and right of a fixed cross configuration on their screen.
(13:40):
He compared this with how good participants were carrying out
the task to spot matching letters in the left and
right visual fields, which will require them to use the
same parts of the brain at the same time. Um
extreme left handed individuals, those people in the spectrum extreme
lefties were forty three milliseconds faster at spotting matching letters
across the right and left visual fields than their right
(14:02):
handed compatriots. So again you're talking about a more symetrical brain,
a larger corpus clos um transmitting that information. So even
if someone is swinging at you and you've trained against them, um,
and you swing against them, they're they're taking in the
data quicker than you are. Well. Um. I mentioned earlier
(14:25):
about how war torn areas you might see an increase
in the number of left handed individuals in your myths,
and this comes back to a study from Para French
researchers uh Charlotte Foi and Michael Raymond. This is between
two thousand and one and two thousand four. They tested
the theory of lefty battle supremacy by examining the prevalence
of left handed citizens in area with areas with high
(14:47):
murder rates, because in theory, these conditions would allow them
a better chance to observe at least statistically the left,
the lefty survival of the fist. And sure enough they
found that lefty population percentages in these areas win as
high as twenty seven percent, so again up from ten
percent of the population to because there's that much face
(15:09):
stabbing going on that the lefty face stabbers are going
to actually sustain their population, whereas the righties are going
to die of their face wins. Okay, so you have
some negative connotations of like schizophrenia, dyslexia, and so on
and so forth, but now you have criminality added to
It's just the culture itself is falling into criminality and
(15:31):
falling into violence. And you can't blame the lefties for
just being better at stabbing people in the face. That's
just that's just a fact, right, But an unintended consequence
might be that those lefties watch out, they're gonna shrank yea, yeah,
I mean its survival of the Fittestralia. Well, okay, so
that's playing to this idea though, that that lefties are
inherently sinister. Yeah, there's something off about them, that their
(15:54):
their skills seem a little better. And we can either
chalk that up to again the inner workings of their
rain and how they have to to to deal with
a righty world, or it could be that they have
a touch of the devil, as say, it was a
pact with the devil. Right. Um. We look at at
the left and the right in religious terms sometimes, and
this is because if you look at text, you'll see
(16:16):
that Jesus ascends to heaven on the right hand of God.
You have a virginal reference of descending into hell on
the left, and so you also have um. You have
also have it ingrained in language like an Italian, the
word for left is sinistra, which means sinister. So these
(16:38):
things are already at playing here for the giving us
this idea of how to proceed with lefties. And we
just did an episode on symbols and how that is
silently guiding us in the way that we perceived the
world around us. Yeah. In the English language, right means
both correct and right side. In our politics, left tends
(17:00):
to denote the more radical side, um, the more left
field right field versus right field. And and then you
have things like left handed compliments where it's a compliment,
but it's it's like a vile compliment that is meant
to to drive home some sort of an insult. And then,
of course, in various cultures, is also the idea that
(17:20):
the left hand is the wiping hand for the for
the pooh, and therefore to shake with the left hand
is is frowned upon, or to do anything with the
left hand. Okay, but what if what if the population
all of a sudden we're lefties, Well we'd have a
lot of stuff to change, right, I mean all the desks,
which because suddenly the lefties there, this would be their
(17:42):
dream scenario. Suddenly they're in charge, they would probably wipe
the rest of us out. It's true, Um, And I'm
just gonna predicate this on a study. It's a two
thousand eleven study published in Psychological Science by Daniel Kasanto.
And the idea is that you reverse the symbols of
and bad right and left. It's like, yes, it is
(18:04):
some some who have them and some who don't write
and uh, what they are doing is they're saying unconsciously,
right handers associate good with the right side of space
and bad with the left. Now, of course, people who
are left handed do not have the same association. They
think the left hand and the left spaces are perfectly fine.
This is what they found out when they messed with
(18:25):
hand dominance. And what they wanted to do first, though,
is they wanted to look at language and this idea
of positive things being associated with the right side. And
so to test this, they were asked, um, you know,
right hand participants were asked which of two products to buy,
which of two job applicants to hire, or which of
(18:45):
two alien creatures looks more intelligent? Um. Right handers tended
to choose the product, person, or creature they saw on
their right, and most left handers, most of them chose
the one on their left. Isn't that amazing that just
in this spacial confige duration you can put person to
a on the right, person be on the left, and
if you're right handed, you're you're more apt to hire
(19:06):
that person or to think that this person or creature,
alien creature, is more intelligent than one on the left.
And yet not to complicate via scenario that every time
we look in the mirror and we consider the person
most central to our view of the world, we're looking
at a we're looking at a reflection, we're looking at
a reversal. Um. But I think you're onto something. You're
(19:28):
about the correcting of right and left in terms of
their moral qualities, and about this this glove. Yeah, well
this glove. The researchers put this on the right handers
and the left handers, um, and they performed a motor
fluency task while wearing this really bulky glove, and it
turned these right handers in temporarily into left handers. And
(19:50):
about only twelve minutes of this lopsided motor experience, the
right glove participants judgments on an unrelated task showed a
good it is left bias like natural left handers do.
So it shows that you can just change up the
scenario and actually have the bodily experience change your psychological experience. Yeah.
(20:12):
So it's essentially Sylvester Monkey mcmonkey McBean's uh star on
or star off machine this glove actor SEUs Yeah, and
gazing into the future and considering this possibility of of
suddenly they're being lefties. I can imagine them rounding up
all the rights and making us wear those gloves so
that they can change the way that we view the world.
(20:34):
That might not be a bad thing, right, because did
you hear that all the time? Like you should change
the hand that you brush your teeth with because it's
good for the brains, good for the brain. Right, So
what if we decided all to do this? Is it possible?
What would happen if we changed our handedness? I think that,
I mean, it's worth worth drying. I want to do
more of it because I was trying to think on
the right end this morning. I was thinking, what do
(20:56):
I do with my left hand? Um, I if I
if my right hand is occupied, then I may use
my left hand to drink water or whatever or if
I'm on the train, I may read with my left
hand while I'm holding onto the bar with my right.
But for the most part of THO like, I don't
do enough with it outside of the manipulation of various
computer gadgets well. And as a result, actually your your
(21:18):
nerves are less developed. And that's that side of your hand,
by the way, um, because it takes a while if
you're going to switch hands to try to build up
his connections. It makes sense, right, because it's more of
a pathway that's being used. And people who have sustained
injuries now this and they're not able to use their
left hand. Um. Actually, according to poor act that she's
(21:39):
the professor of psychology that I had talked about before,
one student that she studied who had been in an
accident that permanently injured his dominant hand was able to
eat with a four and other basic activities work just fine,
but when it came to um cursive writing versus printing,
he had a lot of trouble. I mean, printing was fine,
but it turns out that when he was trying to
(22:01):
write in cursive it was a bit of a nightmare.
And that's because these two actions come from different regions
of the same part of the brain, and there's a
strip across the parietal lobe here. And handwriting is a
fine motor skill, while printing is not. So not everything
can be sort of perfect, even if you are building
up those neural connections in your non dominant hand. Well,
(22:24):
I was always a nightmare when I was trying to
do cursive weaven with my dominant hands. So you know,
I was writing a note to my daughter's teacher. For
some reason I did in cursive. I guess I was
trying to be fancy, and it was very hard because
you know, in this day and age, it's very seldom
that I actually write print anymore, let alone use cursive handwriting.
Kind of hurt my brain a bit, all right, So
(22:46):
I want to give you one more extreme example of
becoming a lefty, and um, this can be found. Actually,
the evidence of this can be found at the medieval
Fernie Hurst Castle in Scotland. Uh So, just consider this
fact that historically in castle's staircases are built so that
the defenders at the top have their sword free to
(23:08):
swing at opponents, while invaders have their swing impeded by
the wall, so they're thinking about this when they're building
the castle, like, how what's the advantage when I'm using
my sword at the top and I'm trying to defend.
According to Sally Lincoln Auger, she's a perceptual scientists at
the University of Virginia, the Warrior clan care at this
castle trained to use their weapons in their left hand,
(23:30):
and even fitted their castle with a staircase that's tricked
out just so that it could allow their left hands
to wield a sword at invaders. And the ancestors of
the clancare are all right dominant. So the idea here
is that they weren't all, you know, miraculously lefties. They
just knew that there was a lefty battle advantage, and
(23:52):
so they actually train themselves to take advantage of that
that advantage. Yeah, I thought that was pretty impressive. That
is all right, Well they you have it, um a
little insight into the world of lefties for you right
es and uh, a little more self knowledge for you lefties.
I already knew you were awesome, admitted. Yeah, they're they're
pretty rag out their their powers and and but but anyway,
(24:15):
we we love our lefties and our righty listeners. So
Please don't take anything I said at the top of
the podcast too heart. Just take the science that we
talked about too hard or to brain. Yeah, and by
the way, Noel's left hand is lifting a little bit
beat right and underneath all that, oh yeah, we need
to we need to unstrapped in there. All right. Well,
on that note, then we're gonna go ahead and sign
out here. You can find us in all the normal
(24:35):
places if you want to reach out to us and
tell us about your experiences as a lefty in a
right handed world, or your experience of variety living with
a lefty all of its fair game, or let us
know what you think. But you can find us at
stuffable in your Mind dot com. You can find us
at on Tumblr and on Facebook is stuff abow your Mind.
On Twitter we are Blow the Mind, and on YouTube
were Mind Stuff Show. And with your left hand. You
(24:57):
can write us an email and you can do so
at blow them d at discovery dot com. For more
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