[HN Gopher] Handedness as a determinant of lateral bias in human...
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       Handedness as a determinant of lateral bias in human functional
       cradling (2023)
        
       Author : Tomte
       Score  : 40 points
       Date   : 2024-02-26 10:45 UTC (12 hours ago)
        
 (HTM) web link (onlinelibrary.wiley.com)
 (TXT) w3m dump (onlinelibrary.wiley.com)
        
       | JR1427 wrote:
       | I just looked back at some photos to confirm that I cradled our
       | daughter right-sided.
       | 
       | I'm right-handed, but do some other things left-handed too, like
       | holding the knife in my left hand while eating. This has always
       | seems much more logical to me, since the knife is a secondary
       | tool. I hold the fork in my right hand regardless of if my left
       | is holding a knife or not.
       | 
       | I also notice that when raking leaves, or mopping a floor, I can
       | never make up my mind which handedness feels more comfortable,
       | and just switch between them.
       | 
       | But I was very handed when it came to holding our daughter.
       | Always her head on my right side, whether cradling or with her
       | head on my shoulder. I didn't have a problem doing simple tasks
       | with my free non-dominant (left) hand, but cradling a baby seemed
       | too important a task to give to it!
        
         | ubercore wrote:
         | I play hockey left handed, but do everything else right handed.
         | Has always felt natural to me, I can't remember ever doing
         | differently.
        
         | toxik wrote:
         | > I hold the fork in my right hand regardless of if my left is
         | holding a knife or not.
         | 
         | Same, unless I'm cutting roast beef with a kitchen knife where
         | the knife is the primary utensil.
         | 
         | I think I could easily do the cutting with fork-left/knife-
         | right, but as soon as I imagine the actual placing food into my
         | mouth, I want my right hand.
        
         | tudorw wrote:
         | For fun, try switching the left and right mouse button actions,
         | just give it a whirl, bizarrely I just took to it like water
         | despite decades of muscle memory?!
        
           | tmellon2 wrote:
           | It is because you are using your dominant hand. Try switching
           | the mouse with your non-dominant hand.
        
             | pixl97 wrote:
             | I'm from that generation where they were just getting over
             | trying to make left handing kids right handed. Now that I'm
             | older I find myself doing all kind of weird things...
             | 
             | For example as a kid I had to use left handed scissors or I
             | couldn't cut things, now I use right handed scissors in
             | either hand. I switch my mouse to my right and left hand
             | sometimes without thinking about it. My brain just
             | transparently maps the right click to my left hand index
             | finger. I throw with my right arm and shoot right handed,
             | but when it comes to tool use I seem to be ambidextrous.
             | This said, I can only write with my left hand.
        
         | lukas099 wrote:
         | > the knife is a secondary tool
         | 
         | It is secondary overall, but during the act of cutting itself
         | it is the primary tool -- the fork merely holds the food in
         | place. Thus the differing "European" and American etiquette
         | standards for utensil-holding (maintain fork in left hand vs.
         | switch when cutting).
         | 
         | ("European" in quotes because it is not ubiquitous across
         | Europe [1])
         | 
         | [1] https://en.wikipedia.org/wiki/Eating_utensil_etiquette
         | 
         | What is most interesting to me is that we even have these
         | arbitrary standards for social class judgement.
         | 
         | When I was in Europe I made myself surprisingly uncomfortable
         | trying to emulate the utensil etiquette of the people I was
         | eating with. It was doubly painful when we ate pizza, which I
         | wanted to pick up, fold in half and eat with my hands.
        
           | cnity wrote:
           | My read on the utensil thing is that basically keeping the
           | fork in the left hand feels more "rushed" and therefore less
           | delicate/dignified. I'm from the UK and my wife is American,
           | and when I'm over there I do notice that if I forget to adapt
           | my technique I sort of feel a little undignified in the way I
           | eat, comparatively. It's interesting.
        
         | brvsft wrote:
         | > I also notice that when raking leaves, or mopping a floor, I
         | can never make up my mind which handedness feels more
         | comfortable, and just switch between them.
         | 
         | I feel similarly. I think with a lot of these tasks, the stakes
         | are low and the dominant hand can have an adequate effect in
         | either placement.
         | 
         | On the other hand (ahem), I do not feel this way about
         | shoveling snow. I have to use my dominant hand on the far end
         | of a snow shovel because I can generate more power with more
         | control that way (despite my right arm having less muscle --
         | per my other comment about my experience agreeing with this
         | article, I hold my child with my left arm and now have more
         | muscle on my left arm as a result). I think the aspect of being
         | able to control the power feels more important because
         | shoveling snow feels like, if I screw up the motion, I can
         | potentially cause injury to myself.
        
       | arghwhat wrote:
       | I can't help but think that this is a very anticlimactic and
       | obvious conclusion...
        
       | phyzome wrote:
       | Makes sense. I tend to carry things in my left hand to leave my
       | dominant right hand free for other tasks. And cradling an infant
       | while trying to get other stuff done is very, very common.
        
       | brvsft wrote:
       | I also hold my child with my left hand as I am right-handed.
       | Obviously, it allows me to do more since my dominant hand is free
       | for more complex tasks, as stated in the article.
       | 
       | I only thought about this recently because I had a 'test' on my
       | body that determined my left arm had more muscle than my right
       | arm, and the person administering the test asked if I am left-
       | handed as a result of this. I couldn't figure out why this would
       | happen, thought about it for a day and realized the common
       | repetitive motion I do that might strengthen my left arm
       | significantly is _holding a 20+ lb child_.
        
         | cnity wrote:
         | I always heard that your dominant arm is usually weaker,
         | because it is reserved for fine motor operations while your
         | non-dominant arm bears load. Consider e.g. putting keys in a
         | door while you carry groceries, etc.
        
           | coolsunglasses wrote:
           | Not what I've seen in strength training or among people doing
           | physical labor (including my wife who used to be a
           | carpenter).
        
           | kjkjadksj wrote:
           | I recently had an ultrasound done on both shoulders for
           | reference. The doc said my dominant shoulder looked a lot
           | worse
        
           | bonton89 wrote:
           | I've just heard your mind is better able to recruit strength
           | from the dominate side so your body doesn't need to brute
           | force it with extra muscle.
           | 
           | My left pectoral is noticeably (to me) larger than my right
           | dominate one. Not sure if that is the recruitment effect or
           | if I somehow favor that side when lifting.
        
       | groestl wrote:
       | Now. Does lateral bias in cradling determine handedness in
       | infants as well?
        
         | walthamstow wrote:
         | Wouldn't that mean all/most siblings have the same handedness?
        
         | v8xi wrote:
         | This is what I thought the article was saying until I read it.
         | But if most babies are cradled on the mothers left, that would
         | lead to the babies left side being more interacted with by the
         | mother. Since most sensory information is processed
         | contralaterally you would think it would bias towards left-
         | handedness by strengthening connections in the right brain
         | which is clearly not the case.
         | 
         | However, smell (and taste, but I don't think that is relevant
         | here) is processed ipsilaterally and vision/hearing have some
         | ipsilateral processing so maybe I am wrong and it IS
         | strengthening their left brain and leading to right handedness.
        
       | metaphor wrote:
       | The paper doesn't appear to consider impact of the child's
       | weight, whether the task at hand demands strength/endurance v.
       | dexterity/control, and the related natural strength bias between
       | men and women.
       | 
       | The wife is right-handed whereas I'm left-handed, and we both
       | currently prefer cradling with our non-dominant arm; my
       | prevailing driver is head control (while standing), whereas hers
       | is both head control and dexterity during feeding (while
       | sitting).
       | 
       | Despite our daughter being just a month old and 9 lbs, the wife
       | is already remarking that she's starting to get "heavy". As our
       | child puts on more weight, I'm expecting to see the wife use her
       | dominant arm more to cradle in certain scenarios, predicated by
       | the baby's growth outpacing her arm strength buildup. In
       | contrast, my non-dominant arm is notionally several times
       | stronger than her dominant, so I suspect there will much fewer
       | reasons for me to pivot as the child grows.
       | 
       | As an aside, I truly do find it strange that child weight doesn't
       | appear to be taken into any meaningful consideration. I
       | understand that an innovation out of Europe which spread like
       | wildfire in the US are car seats with rotating carriages (delayed
       | adoption speculatively due to safety regulations). Many years
       | ago, a close friend was first exposed to them when renting a car
       | while on vacation in Iceland; he claimed that the UX of moving
       | his daughter in and out was such a "game changer" that he
       | immediately ordered one upon return, and it was one of the first
       | things he recommended when I was soliciting wisdom in the months
       | before my child was born.
        
         | ecshafer wrote:
         | When the child gets older and bigger, the thing that helps is
         | not having to hold the head. So they get bigger, but you can
         | put the kid on your hip and just hold them around the torso
         | with your arm. So while they do get bigger, some of the issues
         | goes away as they aren't as fragile.
        
         | a_gnostic wrote:
         | A baby sling helps.
        
         | monkmartinez wrote:
         | Lefty here as well, funny thing about my experience with two
         | kids (now teenagers) was that I could get switch arms with no
         | loss of functionality holding a baby. I credit this to living
         | in right hand world. Most lefties I know are at least somewhat
         | ambidextrous simply by fact of most things being built for,
         | taught and learned from right-handed people.
        
           | seabrookmx wrote:
           | I don't know about ambidextrous (being able to perform a
           | skill with either hand), but all the lefties I know are
           | cross-dominant to some variety.
           | 
           | For instance, I hold a pen, fork, soldering iron etc. with my
           | left, but use a mouse with my right.
        
             | monkmartinez wrote:
             | You are correct and I have been using ambidextrous wrong
             | for 40+ years. Never too old to learn something and I did
             | today, so thank you!
             | 
             |  _Cross-Dominant_
             | 
             | 1. Mixed preference: A cross-dominant individual favors
             | different hands, eyes, or feet for different tasks. For
             | example, they might write with their right hand, eat with
             | their left hand, and kick a ball with their left foot.
             | 
             | 2. No clear dominant side: They lack a single, strongly
             | dominant side of the body, leading to a mixed pattern
             | across various activities.
             | 
             | 3. Potential Challenges: Cross-dominance can sometimes be
             | associated with minor difficulties in coordination or
             | activities requiring single-sided precision.
             | 
             |  _Ambidextrous_
             | 
             | 1. Equal Skill: A truly ambidextrous individual can perform
             | tasks with equal skill and control using either hand. This
             | includes tasks that require fine motor skills, like
             | writing.
             | 
             | 2. Rarity: True ambidexterity is relatively uncommon.
             | 
             | 3. Developed Skill: Often, ambidexterity is a learned
             | ability and not an innate characteristic. People can train
             | themselves to use both hands with near-equal proficiency.
             | 
             |  _In Summary:_
             | 
             | Cross-dominant: Mixed hand/eye/foot preference for
             | different tasks. Ambidextrous: Equal proficiency in using
             | both hands for almost any task
        
             | kiicia wrote:
             | I am right handed but I use phone almost exclusively by
             | left hand (when I use only one hand to hold and operate
             | phone, like reading HN now), I am using right hand only
             | when two-thumb-writing (like now)
        
         | kjkjadksj wrote:
         | If the baby is anything like a cat they will have their own
         | side bias to account for too
        
       | BurningFrog wrote:
       | I don't understand the title, so I asked ChatGPT to rephrase it:
       | 
       |  _" How Being Right or Left-Handed Affects How We Hold Things"_
        
         | lazide wrote:
         | Specifically how we hold young children it seems?
        
         | bookofjoe wrote:
         | That's better. But I post this comment knowing that ANY praise
         | of ChatGPT and its ilk here guarantees downvotes. This is NOT a
         | friendly venue for AI. And that's an understatement.
        
           | moate wrote:
           | Commenting on the propensity of a comment to generate
           | downvotes is also a great way to guarantee downvotes,
           | especially if you're not providing much else to the discourse
           | but a verbal upvote.
           | 
           | Discourse on rhetoric.
        
             | bookofjoe wrote:
             | I'm waiting...
        
         | medler wrote:
         | Not really that close, since the most important thing about the
         | title is that it's talking about cradling [babies].
         | 
         | This is a good example of how ChatGPT often gives answers that
         | seem plausible but are incorrect.
        
           | codersfocus wrote:
           | Interesting how study titles might be a good way of
           | determining reading levels.
        
             | etempleton wrote:
             | I don't know, that is a tortured title. I got what it is
             | saying, but it is about as unclear as one can be for no
             | good reason other than to try and sound smart and I
             | wouldn't judge someone's reading level based on their
             | ability to parse that. I guess you could say that equates
             | to reading level, but I think it equates more with one's
             | familiarity with reading terrible academic papers. Which,
             | yeah, I guess is a type of reading comprehension, but more
             | of an exposure issue than anything else.
             | 
             | The paper itself is actually refreshingly clear and direct.
        
       | WarOnPrivacy wrote:
       | We had twins. Here's how I cradled them in crowded public places.
       | 
       | My arms are out, palms up. A baby lays face down across my
       | forearm, head toward my outside elbow. My hand has a firm hold on
       | the upper part of the inside leg, the other leg hangs to the
       | outside.
       | 
       | It's a very secure hold. I can bring them into my chest if the
       | sight of it failed to clear a path.
       | 
       | Oh and I didn't wear a watch.
        
       | etempleton wrote:
       | I think it would be pretty obvious that handedness would
       | influence preference here. I suspect left handed people are just
       | more comfortable using their right hand for every day tasks
       | because many items are designed for right hand use.
        
       | marviel wrote:
       | I wonder -- parents, when you're holding your toddler's hand,
       | which do you generally use -- your secondary hand, or your
       | primary hand?
        
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