Talk:Handedness
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The castle with the anti-clockwise spiral staircase mentioned in the article is Smailholm Tower near Kelso in the Borders of Scotland.
[edit] Information superceded by research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, 1 December 2006 (UTC)
http://dsc.discovery.com/news/afp/20031027/walrus.html
[edit] Shared material with left-handed
- Moved to Talk:Laterality#Merger proposal. Please go there to continue merger discussion.
[edit] Handedness of staircases in castle.
this has nothing to do with sidedness!!!!!! grrrrr! Assume
- The defenders are on the top floor going down.
- The attackers are on the bottom floor going 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.
Attention Noe
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.
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 ....
Tabletop 04:09, 24 May 2005 (UTC)
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)
[edit] Genetic evidence
A 2004 American Scientist article claims that handedness is genetic. [1] I don't know whether it is correct or not, but the inconsistency with the article should be resolved somehow.
- 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/
- 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?
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)
[edit] Proposed merger
- Moved to Talk:Laterality#Merger proposal. Please go there to continue merger discussion.
[edit] 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 21:05, 1 August 2007 (UTC)Megan
[edit] 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".
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.
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)
[edit] Masturbation
Discovery: masturbation with the other hand is as difficult as writing. Please add a note somewhere about this.
[edit] 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)
[edit] 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)
[edit] 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)
[edit] 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)
