Talk:Handedness/Archive 1

Staircase identified
The castle with the anti-clockwise spiral staircase mentioned in the article is Smailholm Tower near Kelso in the Borders of Scotland. —Preceding unsigned comment added by Adambisset (talk • contribs) 23:02, 15 December 2004

Resource intensive human brains.
The human brain is so expensive in turns of resources and energy consumption, that there has to be division of labor between the two sides of the brain. Only some functions can be duplicated. —Preceding unsigned comment added by Tabletop (talk • contribs) 02:22, 23 May 2005
 * The material above was removed without explanation (when adding other material) by at 07:41, 9 November 2005, and is now restored at 06:18, 1 May 2009 (UTC). --Jerzy•t

Handedness of staircases in castle.
Assume
 * The defenders are on the top floor going down.
 * The attackers are on the bottom floor going down up.

The spiral in the staircase should go the way that allows the defender's sword to swing into the centre pillar, for majority right-handers, a swing from right to left. This allows the defender to hit the attacker around the corner, almost. Let us call this a right hand spiral.

The same spiral in the staircase forces a right handed attacker's sword going uphill to swing from right to left away from the centre pillar, and into the outer wall, where it is reduced in attacking power.

This assumes that defenders and attackers are mostly righthanded. If possible, the attackers should use their left handers going upwards, if they have any, to lead the way.

If the defending force consists of lefthanders and they design the spiral of their castle staircases to go the other way, counter-intuitively and counter-productively, they make things easier for a right handed attacking force. A lefthanded spiral in a castle keep staircase suits a right handed attacking forces just fine.

Since attacking forces tend to outnumber defending forces, a left-handed defending force is still better off having right handed spirals in their Castle Keep staircase. ''This wide spacing does not coincide with the end of Tabletop's contribution

Attention Noe -- Tabletop 04:09, 24 May 2005 & 10:34, 26 May 2008 (UTC) I am not disputing the story about the Kerr family with lots of lefthanders, building their castles with lefthanded staircases, but I do think that their effort is futile. -- —Preceding unsigned comment added by Tabletop (talk • contribs) 04:14, 24 May 2005
 * The cryptic reference to the Dab Noe would not have been cleared up even if TT had used "User:Noe", since Noe has piped their sig elsewhere on this talk page with "Niels Ø". Yikes! --Jerzy•t 01:02, 1 May 2009 (UTC) 


 * It appears that this is OR, and a guide to whether we should bother looking for refs to support it, not to what we can put in the accompanying article. In any case, the outer front corners of the steps (to choose a clear point on each one) of a so-called "spiral" staircase trace approximately a helix. Since it is clear to most readers which handedness of bolt is intended when "right-handed thread" is specified, it's seriously confusing to describe (as i think TT has) a counter-clockwise-descending staircase as right-handed (doing so, i assume, simply bcz it is more convenient for right-handed defenders to fight facing down toward the attackers). The convention says it is a left-hand staircase that descends counter-clockwise and ascends clockwise, requiring the climber to keep turning right, and, other things being equal, presumably enhancing the defenders' chances, compared to a left-hand one, where only right-handers are involved. If we grant your arguments, that changes the statement of your conclusions to
 * [What] allows the defender to hit the attacker around the corner, almost[, is called] a left hand spiral.
 * and
 * A left-handed defending force is still better off having left-hand spirals in their castle keep staircase.
 * --Jerzy•t 01:02, 1 May 2009 (UTC)


 * Of course, your reasoning leaves out many factors, perhaps foremost that there are so many factors favoring the defender (striking down from above rather than up advantages the force of the defenders' blows, controlling the space surrounding the staircase may asymmetrically provide protected positions for stabbing at attackers thru loopholes, in the absence of a prolonged siege the defender has short supply lines, etc.) that the main defense is to guarantee that taking the castle by main force will entail unacceptable losses by the attackers. Finally, if you're rich in lefties, go ahead and build to create conditions that don't hinder them, and train them for those conditions. Your right-handed enemies won't be able realize their full theoretical potential for fighting better on your spiral staircase than on the usual right-handed-defender-favorable ones, because they've got to put their training time into getting experience at the more often relevant (and more difficult) task of fighting up a typical one. Your lefties get the same advantage of striking freely down that your righty attackers have to cope with on their righty neighbors' home ground, but the invaders' reflexes will be full of emphasis on defensive measures based the their usual difficulty of striking up on that the awkward side. Odds are in any case that you'll never have to fight them, and certainty that you'd outlast them is not an achievable deterrent. Increasing the likelihood that their cost of outlasting you will be unacceptable to them might do more to deter them, than would reducing your own losses! --Jerzy•t 01:02, 1 May 2009 (UTC)

The key difference between castles and say tennis courts, is that tennis courses are the same handedness either way, whereas a spiral staircase is one-hand going up and the opposite hand going down. This gives a rare left handed tennis player a consistant advantage, whereas with castle keep spiral staircases it depends .... —Preceding unsigned comment added by Tabletop (talk • contribs) 04:19, 24 May 2005

Tabletop 04:09, 24 May 2005 (UTC)
 * The immediately preceding struck-thru sig is a false sig, indeed placed by the contributor of the material above it, but misrepresenting the timing, and confusing the audits that rule out bad-faith forgeries. A copy of the sig has been placed back where it was before intervening, unsigned contribs were made by that contributor.


 * I have changed the article back (more or less), to mention your reservations about the usefulness of Kerr's staircases. --Niels Ø 19:05, May 28, 2005 (UTC)
 * this has nothing to do with sidedness!!!!!! grrrrr! —Preceding unsigned comment added by 137.195.176.12 (talk) 17:29, 25 February 2008
 * The IP placed this at the top of the section, so there's no telling what part of the content they had in mind. 

What makes you right- or left-handed?
What makes you right- or left-handed? It has been known since Darwin's day that left-handedness in humans runs in families, but it is not a simple system.

It appears that one gene (labelled 'D') causes people to have the textbook 'normal' asymmetries of the brain - leading to features such as being right-handed and probably also having the language centre in the left half of the brain and having hair that whorls clockwise on the head.

An alternative version of the gene (labelled 'C') is thought to fail to determine which side of the brain each specialised area will develop in, and so each such area has a 50 per cent chance of developing in either the left or right side.

This system means that people who have two copies of the 'D' gene will be right-handed (as well as having hair that whorls clockwise and a 'normal' brain configuration).

Taking sides People who carry two copies of the 'C' gene will have a 50 per cent chance of being left-handed - and are also thought to have a 50 per cent chance of every other asymmetry of the brain being in the opposite hemisphere from 'normal'. This explains why identical twins (which have the same genes) sometimes have different hand preferences.

People who have one 'C' and one 'D' gene have a 25 per cent chance of being left-handed and probably also a 25 per cent chance of each specialised region of the brain being in the opposite half from 'normal'.

So, if you are left-handed then you must have at least one 'C' gene. But, some right-handers will also have the 'C' gene - another external clue seems to be hair whorling anti-clockwise on the head, which is now also thought to indicate the presence of the 'C' gene.

If it is true that other areas of the brain are also affected by the 'C' gene, it might explain why left-handed people are over-represented among people with speech difficulties, schizophrenia and dyslexia - and some people with a 'C' gene may have a brain make-up that makes them particularly talented compared with 'normal' 'DD' people.

— Preceding unsigned comment added by 85.96.87.27 (talk) 21:03, 30 August 2005
 * The above material was removed by 21:14, 4 September 2005}} without explanation, and is now restored at 06:18, 1 May 2009 (UTC). --Jerzy•t

Genetic evidence
I was hoping somebody could address the entire section on genetics. A statement like this, "Left-handers comprise almost 20% of the mentally retarded population and 28% of the severely and profoundly mentally retarded population." without providing any kind of scientific backup is outrageous. This entire paragraph, as well as the next, appear to be the arbitrary opinions of someone with a sketchy scientific background. —Preceding unsigned comment added by 68.10.90.218 (talk) 22:58, 5 October 2009 (UTC)

A 2004 American Scientist article claims that handedness is genetic.  I don't know whether it is correct or not, but the inconsistency with the article should be resolved somehow. —Preceding unsigned comment added by Schlafly (talk • contribs) 18:59, 13 January 2006
 * No, that gives the current picture, which matches the data; it's partially genetic. Since identical twins can have different handedness it can't be totally genetic. But if you get one gene, you're righthanded, if you don't get that gene, then it's environmental. So, it's a mix. Gzuckier 19:31, 31 July 2007 (UTC)
 * Now that I look at the article (here on wp) again, i don't see that this is made clear. Hmm. Gzuckier 19:34, 31 July 2007 (UTC)

Right Hand, Left Hand (Chris McManus) gives a considerable amount of information on left-handedness being genetic, and this view is supported by a wealth of evidence. I believe the original author's view that it is not on this is almost certainly incorrect.http://www.righthandlefthand.com/ — Preceding unsigned comment added by 82.39.209.69 (talk) 23:07, 2 February 2006
 * My understanding is that lefthandedness is believed to be induced by increased levels of testosterone present in the womb. If that's true then lefthandedness per-se would not be genetic - but the tendancy for there to be excess of the hormone might well be.  It is known that twin boys (not necessarily identical twins) have an increased tendancy towards lefthandedness due to the 'double dose' of testosterone the two brothers are getting.  The probability of bearing twins would have to be genetically linked to the mother - not to the child - so the child might wind up being lefthanded without ever inheriting this hypothetical "high probability of male twins" gene from the mother.  If the foetus produces more testosterone than usual during early development then that might be a direct genetic link to the child.  So I don't think we can possibly be talking about anything as simple as "this little bit of DNA makes you left-handed" - but genetics clearly does have something to do with it.  As with many such things, it's got to be a balance between genetic predisposition (both of the child and the mother) and environmental factors so we probably won't get a clear answer to this question. SteveBaker 18:58, 22 November 2006 (UTC)

Well, I'm left handed and in the last 100 years, so have all my female direct ancestors on my mothers side. Coincidence? PayneXKiller 21:27, 23 June 2007 (UTC)
 * that's well within what you'd expect to see via chance even if there were absolutely no genetic link. Assuming yourself and 3 other generations (since you don't specify), that leads to a basic probability of around one in ten thousand - how many people do you think have read this article? —Preceding unsigned comment added by 82.0.177.233 (talk • contribs) 14:38, 31 July 2007
 * Actually, it's me and 5 generations. And my ex girlfriend who is also left handed has a 4 generation backlog. Pretty big coincidence. PayneXKiller 23:35, 8 September 2007 (UTC)

Information superceded by research
The information contained in this article is human-biased. It turns out that preference for a hand/claw/paw is prevalent throughout the animal kingdom and is therefore "genetic" though testosterone dosage in the womb could be a part of that, I suppose. And deviances from the animal kingdom might result from natural selection. Anyway here is a raw pointer to an article. There are many others.Student7 03:57 (2 edits), 1 December 2006 (UTC) http://dsc.discovery.com/news/afp/20031027/walrus.html —Preceding unsigned comment added by Student7 (talk • contribs) 03:57, 1 December 2006
 * Great ref, but i invite you to try out a six-month moratorium on the term "animal kingdom". The ref not only doesn't use it, but explicitly limits its assertions to vertebrates. (I'm relieved we won't be subjected to a revival of "... when the worm turns.") --Jerzy•t 20:19, 1 May 2009 (UTC)

Masturbation
Discovery: masturbation with the other hand is as difficult as writing. Please add a note somewhere about this. — Preceding unsigned comment added by 61.219.36.143 (talk) 01:04, 7 July 2007
 * I find masturbation with the left hand more natural, despite being right handed. Your assertion sounds like self-research...  —Preceding unsigned comment added by 71.182.32.45 (talk) 18:36, 9 December 2008 (UTC)
 * Indeed, naked self research, by me, I see, who was to scared to login to post that, back in 2007, from the Taiwan IP address I was using that day! Jidanni (talk) 21:20, 1 August 2010 (UTC)
 * Thanks, ladies! I'll put those vivid images to work! --MadWank 06:18, 1 May 2009 (UTC)

Handedness in twins
Please also include some discussion on handedness in identical (monozygotic) twins. Typically, one twin will be left-handed and the other right-handed - not sure of percentages. Additionally, some left-handed people may have had a twin in utero who did not complete gestation. 72.179.166.33 21:04 & :05, 1 August 2007 (UTC)Megan

In animals
This section should be added. I know that I've heard about handedness in animals somewhere, and I'm sure it exists. Someone wanna do a little research? --208.115.202.219 01:08, 10 August 2007 (UTC)
 * I know horses have handedness (eh, hoofedness). That is, they execute turns/etc. better in one direction than in the other, perform asymmetrical gaits better on one side than another, and work in a circle better in one direction than another.  I won't be contributing to the article, but I wanted to show moral support... 24.211.245.220 (talk) 21:24, 20 September 2008 (UTC)
 * But the |article clearly states "Handedness is an attribute of human beings...". Help! Jidanni (talk) 04:06, 28 December 2008 (UTC)
 * Animals do exhibit a preference for laterality, but it's not what could be called handedness, i.e. it doesn't have to do with hemispheric specialization for language and it's found to be more like 50/50, not 90/10. The exception is with non-human primates; they do exhibit something closer to human handedness because they have some limited capacity for language.  Source was an article I Google-Scholar'ed quickly: Fagot and Vauclair, "Manual Laterality in Nonhuman Primates: A Distinction Between Handedness and Manual Specialization", Psychological Bulletin, 109, 1, 76-89. Phtalo (talk) 11:58, 17 May 2009 (UTC)

The origin of right-handedness: Was it the way mothers carried their children?
In a popular German book about language and its origin, I found a compelling theory about how right-handedness may have developed. It runs like this:

The heart is (for some reason) on the left side. Because children are soothed by the sound of the heartbeat, possibly because it is familiar to them from pregnancy, mothers instinctively carried their child so that is was closest to the mother's heart. Before prehistoric carrying slings were developed, this meant carrying it with the left hand. This, in turn, left the right hand with most of the tasks that required fine motor skills. And that, according to the theory, is how right-handedness came about.

The theory is taken from So kommt der Mensch zur Sprache (How mankind acquired language / how humans learn to speak) by Dieter Zimmer, a writer and frequent contributor to the weekly newspaper Die Zeit. I don't have the book at hand right now, so I don't know whether Zimmer provides any references, and I don't know the page number, but I will provide that within the next few weeks.

Personally, I find the theory quite convincing, so I think it should at least be mentioned.

Tracerbullet11 16:07, 4 September 2007 (UTC)

Nonsensical statement?
The statement "Lastly, since other people do not have a spoken language (at least of the type we have) there would be no stimulus for right-handed preference among them, and that is true" is incomprehensible to me. Who are "other people"? Other than whom? As far as I know, people do have spoken language. and what is this "at least of the type we have"? Who are "we"? I don't get this weird "we" versus "other people". Surely, anyone who is a person might be reading this document and therefore might be regarded as part of "we". I think someone should just delete this uncited line if nobody jumps up to defend it anytime soon. Xezlec (talk) 20:47, 23 December 2007 (UTC)

Dubious epilepsy poll
 A single editor offered an indented quotation, then proceeded to comment on it without indentation:  "Also, a Sept 18th 2007 informal poll at the Epilepsy Foundation came up with a dramatic skew in percentages of handedness among epileptics of 19% right-handed, 24% left-handed, and 57% mixed or ambidextrous."

I don't like this sentence. The main reason, aside from the fact that there's no citation, is that it's an informal poll, thus conducted without any scientific rigor, and thus can be interpreted many different ways. The results are essentially meaningless.

For example, consider this highly OR interpretation of the poll that I came up with. Most lefties I know are somewhat proud of their left-handedness, probably stemming from the basic human need to feel special or set oneself apart from the crowd. Therefore a lefty is more likely to, without hesitation, report left-handedness.

A righty, on the other hand, does not have this luxury, but yet still retains the same human need to feel special. Thus, when presented with a multiple-choice questionnaire (or especially a public "hand-raising" poll, which this could have possibly been), the righty is much more likely to see the one or two little things he can do with his left hand and say "hey, I'm mixed-handed!"

Therefore, it's very possible that a large percentage of the self-reported "mixed" and "ambidexterous" people are in fact righties convincing themselves that they're special.

Without the scientific formalities designed to minimize the effects of such psychological factors, the poll results are essentially meaningless.

Oh, and yes, there's no citation. Mbarbier (talk) 14:46, 9 July 2008 (UTC)


 * Nobody's come out to defend this, so I'm gonna be bold and delete this poll. Mbarbier (talk) 15:19 (2 edits), 3 August 2008 (UTC)

droit(e)
I changed the passage about French words (but there's still room for improvement). The word droite is a feminine adjective; la droite is elliptical for la main droite (the right hand). It is thus not only "related" to droit meaning 'straight', it is the same word. —Tamfang (talk) 10:02, 4 October 2008 (UTC)

Questionable Section
I feel like the following section not well supported, and would like to ask you guys how you feel about removing it.

"Asymmetry of internal organs

While the external organs are highly symmetric, the internal organs such as heart and stomach are highly asymmetric. Perhaps the asymmetric brain piggybacks onto this.

Some ambidextrous individuals note that they prefer sleeping on their right side, putting less overall weight on the heart-side of the body. Perhaps this unconscious preference to elevate the left side of the chest cavity to reduce the amount of work that the heart must exert during sleep favors the right side by supplying extra blood (due to gravity), widening the diameter of vessels within the right side of the body to compensate for the increase in pressure, thus, over time increasing that side's muscle efficiency."

The quote above reads a lot like an essay to me. I feel like it's probably WP:OR, especially since no citations are included. – Novem Lingvae (talk) 08:53, 31 January 2009 (UTC)


 * Agreed, it's so very speculative without sources. I also don't see the content of this passage as being relevant at all.  Phtalo (talk) 12:14, 17 May 2009 (UTC)

Lessen duplication?
I agree that Lateralization and Handedness should probably not be merged. But i came to this talk page bcz of a sense that there is excessive duplication among
 * Handedness
 * Right-handedness
 * Left-handedness, probably
 * Mixed-handedness and
 * Ambidexterity, and perhaps
 * Lateralization of brain function.

Excessive overlap is onerous for users reading more than one of the suite of articles, and may further be the vehicle for PoV-forking re social aspects handedness, or re pet theories on the emerging science. IMO these problems are impracticably clumsy to clean up, in the absence of a rough consensus on where the various overlapping subtopics should be thoroughly covered, leaving the other articles in the suite to make reference to the appropriate section elsewhere, probably with brief passages setting at least one of the two pages in the other's context. This talk page struck me as the right place to look for such a consensus; having plowed through it and found only the lks to the merge discussion, i expect that it does not yet exist (but would be grateful for a lk if it does). Am i wrong in thinking that such a consensus is both useful and feasible? --Jerzy•t 05:10, 2 May 2009 (UTC)
 * At the risk of rushing that process, i'm redoing the lead sent of Right-handedness, which i find awkward anyway, and essentially discarding both clauses of the third sentence. Seeing no interest yet in the suite-wide organization issue, i'll justify this for the time being only at Talk:Right-handedness . --Jerzy•t 18:24, 5 May 2009 (UTC)

Clusterizing this talk page
There are now 18 sections on this talk page. While we can usually get along w/o much attention to organizing the talk, it's hard to get a grasp of what's been worked out already. I propose to subordinate most of the existing sections into sections for related topics, roughly as follows: (The numbers represent order in the talk page's current state.)
 * Consequences
 * 1
 * 4
 * 10
 * Talk & Article Organization
 * 2
 * 7
 * 19
 * 20
 * Etiology: theories and potential evidence
 * 3
 * 5
 * 6
 * 9
 * Language
 * 8
 * 14
 * 15
 * 11
 * 12
 * 13
 * 16
 * 18
 * 17

--Jerzy•t 05:10, 2 May 2009 (UTC)

First edit on wikipedia
So, sorry if it wasn't very good.

I just trimmed a few words that seemed to specify an advantage in unarmed combat, when there's no reason to believe it wouldn't also be true with a sword or spear in the left hand.

I also changed the link to boxing to a more general link to combat sports, since the advantage is enjoyed in all striking combat sports (but generally to a lesser degree in grappling). Stuessi (talk) 07:26, 11 August 2009 (UTC)


 * As someone who studies Historical European martial arts, I would like to agree. It is no different, whether you are armed or not, handedness will affect it in much the same way. It is well known that left-handed people have an advantage in sword-fighting, as they are used to fighting right handed people while the reverse isn't true. Also at least one later (19th or 20th century) military sabre manual (maybe Swedish, I don't remember), uses "inside" and "outside" instead of left and right, with the instruction to train all the techniques equally much with both hands. —Preceding unsigned comment added by 213.113.55.165 (talk) 03:13, 18 December 2009 (UTC)

Age of identifying handedness
I came here hoping to see what age one could identify whether a child was right- or left-handed. If anyone knows that, please add it to the article. moink (talk) 14:31, 5 November 2009 (UTC)

In Religions
The article mentions Islam sources that good deeds be done with the right hand. There are also Jewish sources for the same thing especially in the context of giving charity. One possible source for this is PSalms "He stands at the right hand of the needy". Give with the right hand into the right hand of the recipient. There is also the new testament (Jewish Based) source Mathew "But you, when you do tzedakah [charity], don't even let your left hand know what your right hand is doing." which may be taken literally.

Of course the "custom" to wipe yourself with the lest hand is a universal one for the simple reason that most peoples ate with their right hands and did not have toilet paper or running water.

genes?
i think your handedness is determined by genes. just a guess, but it makes sense right?

the right hand would be the dominant gene and left hand is recessive. that explains why more people are right-handed. one of my brother's friends is left-handed, but the rest of his immediate family is right-handed, so maybe his parents are heterozygous.

98.234.178.254 (talk) 01:50, 8 July 2010 (UTC)

Advantage In Sports
I recall reading -- once -- that left-handed bowlers have an advantage because the path of alley surface that their ideal roll (beginning on the left side) normally traverses is less-traveled. I.e., the righthanders wear the finish off their ideal path (beginning on the right side), and that surface gets rougher, while the lefty equivalent path retains its slick finish far longer. Someone may be able to find a citation. WHPratt (talk) 13:27, 22 July 2010 (UTC)

-- I don't know where to begin with this article. As an expert on handedness and cerebal laterality, I don't subscribe to the view that handedness or cerebral laterality in humans is in any way genetic and I proposed in a major theoretical review in Psychological Review in 1991 that there is strong evidence for a prenatal basis for handedness and cerebral latertalization, stemming from vestibular asymmetry. There is counter-evidence from twin studies and no one has yet identified a gene for handedness in the general population. The evidence against a genetic bases was again discussed in Chapter 1 of my recent book entitled "The dopaminergic mind in human evolution and history". I don't how I can present this evidence in the Wiki article but I assure you that my view is supported by strong and legitimate scientific evidence -- not the absurd conjecturing involved with the sword and shiled, ultrasound, spearing, etc. hypotheses. I also reviewed every major disorder with elevated non-right-handedness in Developmental Neuropsychology in 1996 and concluded that deviations from normal right-handedness only occur in disorders with vestibular abnormalities or lack of vestibular asymmeties.

Also, the notion that handedness confers any real evolutionary advantage was completely demolished in a major review in Psychological Bulletin by Hardyck and Petrinovich (1977), who showed on average no difference between left-handedners and right-handers in intelligence or athletic ability.

I have never contributed to a Wiki article but I find this one particularly inadequate given my expertise in this area. If any one who knows how I can revise this to better fit the facts, please help me! (My email is fprevic@sbcglobal.net).

Thanks,

Fred Previc —Preceding unsigned comment added by 66.143.245.206 (talk) 14:57, 22 August 2010 (UTC)

Wow. Good to know that 17% of the population are "abnormal" in your (pseudo)scientific analysis. This is a good illustration of how prejudices in previous generations against non-whites, women, gay people etc gained a veneer of scientific credibility. Even your language "non-right-handedness" (instead of left-handedness) and "normal right-handedness" betrays a bigotted mindset. Left handed people (such as myself) have put up with unbelievable discrimination in the past, and thankfully less so in recent years. Defining us as "abnormal" is not a positive development. Thanks anyway for your "contribution". — Preceding unsigned comment added by 124.158.16.35 (talk) 06:44, 6 June 2012 (UTC)


 * Perhaps a little more time spent on comprehension would lead to lower stress levels for you. Mr Previc's only mention of "abnormality" was in reference to "vestibular abnormalities", which is a perfectly valid medical definition. No where did he describe left handers as abnormal. The mention of "normal right-handedness" is a description of the usual distribution of right-handedness in the general population. And non-right-handedness describes more than just left-handedness. WP:SOAP, so please don't try to make it one. LightYear (talk) 04:35, 12 June 2012 (UTC)

Biological
The fact that human internal organs are arranged asymmetrically may have a major impact on handedness. With very rare exceptions, humans have their heart on the left side of the body.

In primitive combat, it should be an advantage to hold a sword in the right hand, to more easily attack an opponent's heart. Additionally, having one's left hand free to hold a shield over one's own heart is advantageous.

Therefore, if you begin with a population evenly divided between righthanders and lefthanders, once the Iron Age rolls in, things change: The southpaw swordsmen are going to suffer more fatal wounds (in the long run), taking genes for lefthandedness out of the survival competition.

(Now, would we reach a point in time where the relative scarcity of sinister swordfighters began to give them an advantage over righthanders who were unfamiliar with fighting a lefty? I don't know.  Maybe new weapons took over before that happened.)

So, if today, lefties have an advantage in one-to-one sports (including competetive fencing), it was purchased at dear cost to their ancestors.

I'm sure that this theory has been seriously advanced by some expert at some time. WHPratt (talk) 13:40, 22 July 2010 (UTC)

Scientific quality of article is poor, citations not prevalent also
This page is one of the poorest I have seen in a while on wiki. Someone seemingly has just written what they believe in parts without reference or citation to scientific data. Uncited and poorly sourced material should be simply be deleted. My suggestion is deleting sentences sourced by anything other than peer reviewed journals. — Preceding unsigned comment added by 169.234.135.13 (talk • contribs) 08:51, 9 January 201 (UTC)


 * Agreed, I added a Cleanup-rewrite template accordingly. --Fama Clamosa (talk) 09:20, 9 January 2011 (UTC)

this sentence no verb
"Also, during reaching the nonpreferred (e.g., left) hand depending on the complexity of the task and where in the left hemispace the object is located.[7]"

unless someone can provide meaning to this by supplying a verb, I would suggest deleting it entirely. 68.34.57.120 (talk) 17:40, 19 February 2011 (UTC)

Biological theories
The Geschwind–Galaburda hypothesis wikipedia page no longer discusses the left hand theory. That part has been edited out by someone (not me), although I did post the contradiction section. Until the left hand theory is restored on the G-G article, or more evidence emerges to support the testosterone theory... I have removed the Geschwind-Gal. reference from the "Biological theories" section in the handedness article. Witch Hazell (talk) 22:38, 14 September 2011 (UTC)

What about strength?
the article places a big emphasis that this is all about dexterity, not strength. But i thought that it relates to strength as well, with right handed people being stronger in their right hand, and vice versa. However, this may just be because they use that hand more... so i don't know — Preceding unsigned comment added by Darkkelf99 (talk • contribs) 07:20, 18 September 2011 (UTC)

What about feet?
Are some people right footed and some left footed? And, is there any correlation between being right handed and being right footed? (im a lefty, but i think that i am right footed, when it comes to kicking games and such. a few examples where it can matter; soccer, martial arts, playing the drums)

Merger discussion
No discussion regarding the January 2012 proposed merger to this article of the Left-handedness article. I support the proposed the merger since the contents obviously duplicate. Much of the material in the left-handedness article seems also to be a partial copy of Bias against left-handed people. A topic which thus already have a separate article. Academica Orientalis (talk) 16:35, 12 May 2012 (UTC)

Estimates of prevalence missing
Just wanted to say that I came to this page to find out the estimates of prevalence of left-handness. None was given in the introduction where it should have been, and I did not find a section about it. I accidentally stumbled across a mention of prevalence, in "Possible advantages of left-handedness". The article was a near-complete failure. — Preceding unsigned comment added by 82.181.1.63 (talk) 12:15, 31 July 2012 (UTC)


 * Thanks for the criticism. Prevalence is addressed in the third paragraph, which is the first paragraph after the introduction. I think it's fairly prominent but appreciate that you may not see it that way. Did you happen to come to the article via the redirect from left-handed? That article was recently merged into handedness so the emphasis on left-handedness is now less strong. In particular, the introduction is used to describe what handedness is, rather than gives specifics for left-handedness (which is now in the first section). LightYear (talk) 02:44, 1 August 2012 (UTC)

Difference in life expectancy?
Nowadays many experts claim that there is no difference in life expectancy, between right and left handed people. The idea that there is a difference comes from an old study done in 1980, but the method in that study is now disputed. The problem with the 1980-study is that it did not take in to consideration that in the old days left-handedness where seen as a defect, and left handed children where retrained, in school, to be right handed. Too many people where labelled as right handed in the 1980-study, and many experts claim that if that is corrected the difference in life expectancy disappears

Is there someone who knows more about this than me?

/MB — Preceding unsigned comment added by Ee27182818 (talk • contribs) 16:07, 29 August 2012 (UTC)

I remember a large Canadian study from 2000's? that showed significant shorter life expectancy for lefties, that study or further studies on the same dataset showed that it was military service and/or combat that killed lefties earlier, otherwise the life expectancy was the same. A recent (last ten years) very elegant study using photographs of people waving (people tend to wave with their dominant hand) showed lefthandedness declined in the 19th Century at about the rate that schooling increased, in other words schools (or perhaps the Roman writing system) "converted" left-handers, until the 1960's if I remember rightly when lefthanders started asserting themselves Brunswicknic (talk) 18:03, 31 August 2012 (UTC)

Writing Systems
In the context of writing, the article declares the motion is right to left. What about Arabic or Hebrew? Writing systems may be handed, but this article tacitly assumes that all writing systems are right-handed, which is "just plain wrong". —Preceding unsigned comment added by EmmetCaulfield (talk • contribs) 10:41, 26 October 2006 I have added a "cn" tag to the claim that R-to-L writing systems reverse the smudging problem that L-to-R systems pose for left-handers, as I doubt that it is true. Smudging results, not from the direction of the script, but from the position of the writing hand. If the hand stays below the line on which it is writing, it cannot smudge the preceding lines. Right-handed people tend naturally to write from below the line, but that is difficult, with European scripts, for left-handers; and it requires training from a knowledgeable teacher. Left-handers using those scripts therefore often teach themselves to write from above the line, which causes them to smudge the previous lines.
 * The earliest writing systems seem to have been right to left, perhaps because they were invented by lefthanders (17% of the population). But later on, the majority of writing systems tended to be left to right, perhaps becuase righthanders (83% of the population) were now writing a lot, and preferred L-R perhaps because they avoided smudging the ink. —Preceding unsigned comment added by Tabletop (talk • contribs) 10:46, 26 October 2006
 * Cuneiform writing, which preceded paper or parchment, seems to me naturally to flow from right to left, because you're pushing with the right hand. Just my POV. Gzuckier 15:32, 26 October 2006 (UTC)

I have seen only a few people writing in Hebrew or Arabic, but in every case the (right-handed) writer held his hand below the line (with the pen, at least in the case of Hebrew, at right angles to the line, and virtually perpendicular to the paper), and had no problem with smudging. See further discussion of smudging below.

Many ancient Western scripts could be written in either direction or both. There are abundant old texts, in many different languages and writing systems, in which the text changes direction with each line. There are even texts in which the writer wrote from side to side (in alternating directions) until she had filled the page, and then over-wrote that text with lines running from top to bottom (also in alternating directions).

Internationalism and inclusiveness are all well and good, but they should be practiced intelligently, and not as mere reflexes, or they themselves become prejudices. Jdcrutch (talk) 19:02, 2 November 2012 (UTC)

Oldest writing systems written Right to Left
Would it be true to say that the oldest writing systems, of which Semitic languages are some, were and still are written Right to Left? This would suit lefthanders who can see what they are doing and not smudge the ink. Can we infer from all this that writing may have been invented by the minority of lefthanders. Later on, when righthanders started to write too, they changed early writing systems such as Ancient Greek to go Left to Right to suit righthanded writers who were in the majority? Tabletop (talk) 10:41, 26 May 2008 (UTC)


 * I heard once that if you're writing on a stone wall with a chisel it's easier to start at the right. I can't quite picture how this works, though.  —Tamfang (talk) 06:52, 14 July 2008 (UTC)


 * If nothing else, chiseling on stone does not present the problem of smearing ink. —Preceding unsigned comment added by 71.111.205.221 (talk) 21:44, 20 September 2008 (UTC)


 * Actually, the convention of chiseling right to left would favor right handers. You hold the chisel with your left hand and the hammer with your right.  It's easier to chisel from right to left this way if you're a right-hander because the blows come naturally from the right (at an angle).  Conversely it would be easier to chisel from left to right if you were a left-hander.  Phtalo (talk) 12:24, 17 May 2009 (UTC)

Hebrew, Arabic, and Sanskrit are written by hand from right to left. I put a "globalize" tag on the section. --Una Smith (talk) 21:07, 29 September 2008 (UTC)


 * Sanskrit? In which script? —Tamfang (talk) 18:16, 1 October 2008 (UTC)
 * Ah! Okay, delete Sanskrit.  I had no idea it was so complicated.  An expert on Sanskrit taught me to write some words in Sanskrit.  Each word did have had a connecting bar on the top, which judging by the examples on Sanskrit places the script I used in a small category.  I hope that is useful information. --Una Smith (talk) 04:02, 3 October 2008 (UTC)


 * Scripts with a connecting bar (sutra = 'thread') include Dẽvanãgarĩ (used for Hindi and Sanskrit), Bengali, Gurmukhi (used for Panjãbi) – none of which is written RTL. —Tamfang (talk) 05:17, 12 December 2008 (UTC)

"Also, as the left-handed writer moves their left hand across the place where they have just written, smudging may occur."

But this would only be true for those using L-to-R scripts. As pointed out above, it wouldn't be an issue when writing Arabic, Hebrew, or any other R-to-L language. 64.85.225.235 (talk) 05:04, 11 December 2010 (UTC)


 * Why don't people do some research before demanding (or making) changes in the article? Directionality in writing systems has nothing to do with handedness, or all writing would run in the same direction.  Even if we assume that the ratio of left-handers to right-handers is as great among writers as in the human population as a whole (not 17% but closer to 10%), the proposition that such a small, often disfavored, minority could cause the majority to write in the more difficult direction, and could sustain such an inconvenient and inefficient practice for thousands of years, is absurd on its face. Directionality is purely a matter of convention.  It certainly may affect the ease or difficulty with which a left-handed person may use a given system, since any system will inevitably have evolved to suit right-handed writers; but handedness has effectively nothing to do with a society's choice of direction for its writing system, since the overwhelming majority of writers in every known society are, and always have been, right-handed.


 * Jdcrutch (talk) 19:53, 2 November 2012 (UTC)

Historicity
Sorry people, bugbear of mine: Events such as swords, writing, castles etc. are very very recent in human history. At the moment most scholars would argue for the appearance of anatomically modern humans at about 100,000 years ago in Africa, then a migration out of Africa. These humans were anatomically modern, their descendants are all of the same species, the same genotype determining the phenotype, your body is not essentially different from all other humans on the planet, It is extremely likely that the hard-wired stuff was hard-wired at the appearance of the species. What does that mean? Handedness was in place then. The events of the last 5000 to 50 years will have had very little impact on the genetic basis for physical bodies. What happens to an individual body is another thing. 103.23.134.159 (talk) 04:29, 13 August 2012 (UTC) OOps, sorry, wasn't logged on so signature was not identified, I wrote the above but perhaps had a handedness momentBrunswicknic (talk) 04:32, 13 August 2012 (UTC)


 * Handedness is generally thought to be the result of the lateralization of brain function, which is generally thought to be the result (or concomitant) of the development of language. Assertions regarding the existence of language among non-human primates notwithstanding, man remains the only animal that has been found to exhibit either handedness (as distinguished from functional preference between forelimbs for specific activities) or markedly and consistently lateralized brain function throughout the species.


 * It's worth noting, by the way, in response to the last two sentences of the first entry in this section, that recent studies suggest that physical evolution can occur on a much more rapid time-scale than has previously been thought, and that some physical attributes in man (and particularly in geographically isolated groups) may indeed have established themselves within only a few thousand years. I'm pretty sure, however, that neither handedness, language, nor brain-laterailization is thought to be among such recent developments (though Julian Jaynes has offered some compelling, if untestable, hypotheses regarding profound changes in brain organization, including changes specifically involving the lateralization of certain language functions, which he suggests took place within the past 5,000 years).

Jdcrutch (talk) 20:22, 2 November 2012 (UTC)

Bot archive
This talk page is getting very long and the first sections are obviously outdated. I therefore propose that this talk page should be automatically archived by MiszaBot using the following parameters (archive older than 3 months living four threads). Any objections? --Fama Clamosa (talk) 03:11, 5 November 2012 (UTC)

✅ --Fama Clamosa (talk) 17:49, 7 November 2012 (UTC)

Smudging
Smudging is not a function of directionality, or even, directly, of handedness. It is a function of hand-position. Regardless of whether you write from R to L or from L to R, if you write with the hand below the line, you cannot smudge what you have already written (assuming you write from top to bottom; otherwise, the situation would presumably be reversed).

Writing European scripts (at least--I don't know about others) is difficult for left-handers, and, at least until fairly recently, teachers of handwriting have generally had no idea how to teach left-handed pupils--nor even, apparently, any idea that left-handed children even needed different instructions from what the righties got. (Indeed, it was customary in many countries, well into the 20th C., to compel left-handed children to write with their right hands, left-handedness being regarded, at best, as a "weakness".) As a consequence of this prevailing neglect, lefties using European scripts have tended to write from above the line, which is more comfortable, simpler to arrange, and easier to figure out without help.

For left-handed writers of European scripts, writing from below the line usually requires considerably more training and practice than writing from above. It also involves canting the paper at 45°, which makes it especially difficult, if not impossible, to do without a writing table or a left-handed school desk--which are also rare, at least US classrooms. Writing from below the line in, e.g., a hand-held notebook, or on a school desk without support for the left forearm, requires contortions of the hand and wrist that can be terribly uncomfortable.

As a result, left-handers, left to improvise, have tended to adopt the "over-writing" technique, which results in smudging, and not only with "older technologies such as fountain pen usage" (an assertion I have deleted from the article), but also (and in my own experience considerably moreso) with ball-point pens and pencils. I'll note here, moreover (though not in the article, since it's a matter of personal experience), that ball point pens are also problematic for left-handers who write from above the line, because we have to push the pen ahead of our hands, rather than drawing it behind, as right-handers do, so that the metal cup that holds the ball tends to dig up fibers from the paper, which mix with the greasy ball-point ink into a sticky gunk that clogs the pen and stops the ball from rolling smoothly. I have always preferred fountain pens, despite the tendency of some to catch and spatter or blot when pushed along by a left-hander, specifically because their ink does not smudge as much as ball-point ink, which, being greasy, never really dries and tends both to smudge and to accumulate on the side of the hand.

Jdcrutch (talk) 23:26, 2 November 2012 (UTC)


 * Last week I got side-tracked before I read as far as the section, "Handwriting and Written Language". That section suffers from similar unsupported--and I think flatly incorrect--claims regarding alleged differences between L-to-R and R-to-L scripts with respect to left-handed writers.  Subject to the production of some authority to support the section's assertions, I suspect that the writer is presuming, without evidence, that R-to-L scripts don't present a smudging problem for left-handers, purely as a logical extrapolation from the single fact that with those scripts the writing hand moves in the opposite direction.  The section seems to presume that R-to-L writing is, mechanically speaking, simply a mirror-image of L-to-R writing; but if that were the case, one would expect right-handers to smudge their work in R-to-L scripts, which is absurd, given that right-handers control the conventions of handwriting, and they would never adopt, let alone preserve for thousands of years, a manner of writing that caused them to spoil their work on a regular basis.


 * The same section also makes a lot of statements about calligraphy that need to be backed up by authority. Most seem reasonable enough, but the final sentence, "Left-handed people have an advantage in learning 19th-century copperplate hands, which control line-width by pressure on the point;" is false, at least in my own experience, and seems to exhibit the same sort of extrapolation from a single fact as the previous assertion about R-to-L scripts--in this case, that the width of the stroke in copperplate hand is controlled by pressure on the pen.  Even if that characteristic were peculiar to copperplate, which I do not think it is (see, e.g. demonstrations in the film, |"The Art of Hermann Zapf"), the writer offers no basis for her or his surprising conclusion that it affords left-handed writers an advantage over right-handers.  Would that it were so!

Jdcrutch (talk) 22:43, 9 November 2012 (UTC)

Mistakes in the list of lefties
Hi. There are a lot of articles and youtube-videos where among left-handed famous people are names like Brad Pitt, Demi Moore, Tom Cruise, Queen Elizabeth, prince Charles, Robert de Niro etc. But they are NOT lefties, they write with their right hand! I really don't know why people think that for example Brat Pitt is lefty? — Preceding unsigned comment added by Bratislavcan85 (talk • contribs) 14:29, 22 November 2012 (UTC)


 * As much as I doubt left-handed people would want to claim Brad Pitt, I would note that your definition of handedness is flawed: what hand they write with is not a defining indication. Indian cricket player Sachin Tendulkar for instance, signs autographs with his left but is considered right-handed in every other respect. Perhaps you are not considering conversion and/or mixed handedness.--Akafd76 13:39, 14 January 2013 (UTC) — Preceding unsigned comment added by Akafd76 (talk • contribs)

wristwatches
While amusing, the picture of the counter-clockwise watch is irrelevant. However, old mechanical wristwatches were designed to be worn on the left hand by right-handed people, since they had the rewinding mechanism on the right side, allowing easier rewinding with the right hand. The watch shown on the picture also have the mechanism on the right. Corentinoger (talk) 16:18, 21 March 2013 (UTC)

motorized vehicle operation benifits for left-handed might be a little bit inaccurate?
the article describes that vehicle with driver positioned right is advantageous for lefty seems to be little bit off. As an amateur racer and a left-hand person myself, the dominating factor involving driving a car is steering input adjustment, and with a stick shift car, it's actually advantageous for us lefties to be able to steer a car with dominating/left hand while shift with right-hand. Not to mention the dominating eye also focus on the road more.

It's a real advantage for driver's position on the left side of the car, speaking from years of racing experience, especially if one needs to constantly shift up and down with right hand during cornering, left hand controlling ability on steering wheel is crucial. — Preceding unsigned comment added by Zhengjdc (talk • contribs) 23:32, 15 February 2013 (UTC)

Fiupsychology (talk) 04:39, 11 April 2013 (UTC)

Editing Handedness Article - as part as an assignment at FIU
We propose to change the definition of handedness to : A preference for using one hand rather than the other to perform most manual tasks and activities.We also want to incorporate a more scientific aspect of handedness, removing ALL sections that are not relevant. These sections include: sports and handedness, intelligence, politics, etc. At the end of the article where it talks about handwriting, it should be made it`s own article, it should not be included in the Handedness one. We will also include more information and correlations with right handedness ,allowing to fix the neutrality issue. We should remove the section of " mixed-handedness", this is not a MAIN type of handedness. Finally, we want to change up the titles of the sections to make more sense ( i.e: Theories of Handedness Emergence in Humans ) and merge some sections into others. Organizing this article and removing irrelevant sections is a major change we want to carry out.

Samanthav321 (talk) 18:45, 10 March 2013 (UTC)

A couple of quick questions/comments:
 * As the editing goes forward, it's likely that other people will also get involved, which may (or may not) help you towards yr intended FIU goal. Such is Wikipedia!
 * If you haven't already done so, you (and yr prof.) should probably take a look at Assignments_for_student_editors.
 * I hope you don't have some specific editing targets or timeline goals for this assignment? If so, be aware that they may be hard to meet. Again, such is WP!
 * You mention "we" - will more than one person be working on this project? If so, I imagine you would be editing with more than one userid, right?
 * I assume FIU is Florida International University, right? Are you able to share which school/department y're associated with? Also, check this Institution page Education_Program:Florida_International_University and update it if necessary.

Other than that, Good Luck! This article needs lots of attention, so all help is appreciated. jxm (talk) 00:34, 11 March 2013 (UTC)

Hello, we hope to accomplish all edits by the end of April. We are aware of all the edits that can occur that are completely out of our hands, but we hope the wiki community agrees with our changes. It is a group of 3 that is working on this article, but I will be doing all the edits via this user ID. We are working from Florida International University, our advanced experimental psychology class. Thanks for your feedback!

Samanthav321 (talk) 13:55, 11 March 2013 (UTC)

WOW! The recent improvements to this page are quite impressive. It seems like the FIU project has had quite an effect, and I think that the recent removal of the issues banner is justified. (That was done by Emonkee who, I gather, is also linked to the FIU project.) The next question is what do we do about the material that was removed. While a great lot of it was weak and unreliable, it seems that some of the text deserves to be replaced somewhere, possibly on other pages. For example, some - but only some! - of the sports-related and social stigma material appeared to be well-sourced, just not in the right place here. Does the FIU team have plans to establish additional pages for that stuff, or should it all go onto a to-do list? jxm (talk) 01:13, 19 April 2013 (UTC)

I have just come here specificly looking for infomation on the historical/social/stigma aspects of handedness. To find some editor has removed this material seemingly arbitarily is somewhat disapointing. Glover (talk) 04:32, 24 May 2013 (UTC)

Dexterous: confusing wording in this context
I don't feel comfortable enough to change things right away, but I'd like to point out that "dexterous" is quite confusing in this context. The word itself, currently meaning "1. Demonstrating neat skill, esp. with the hands. 2. Mentally adroit; clever." is infact derived from the latin word dexter which means right(hand). At least for me, it felt like the sentence said some people are more right handed with their right hand than there are people who are right handed with their left hand. A latin background is present in a lot of languages today, and since "dexterous" is not a very common adjective the sentence might be quite confusing to people with english as a second or third language (like myself). Thank you for your consideration. 91.176.237.1 (talk) 15:25, 7 August 2013 (UTC)


 * The English word, aristocrat is supposed to be descended from the Greek word, ἀριστερά ("aristerá"), meaning, "left" or "on the left", but is that any reason to avoid calling right-handed or Right-Wing members of the ruling class "aristocrats"? English sanction derives from Latin sancio (= "to make sacred"), and can mean "authoritatively to permit", or "to impose a punishment on". Should we avoid using it because it has two, apparently opposite, meanings? Ambiguity and paradox are just part of life's rich parade.  Jdcrutch (talk) 20:35, 21 September 2013 (UTC)