{"id":2543,"date":"2020-10-08T17:49:31","date_gmt":"2020-10-08T17:49:31","guid":{"rendered":"http:\/\/fitadelphia.com\/?p=2543"},"modified":"2020-10-08T17:49:31","modified_gmt":"2020-10-08T17:49:31","slug":"the-unique-science-of-left-handedness","status":"publish","type":"post","link":"https:\/\/fitadelphia.com\/index.php\/2020\/10\/08\/the-unique-science-of-left-handedness\/","title":{"rendered":"The Unique Science of Left-Handedness"},"content":{"rendered":"\n<ul class=\"wp-block-list\"><li>Dan Robitzski<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><img decoding=\"async\" alt=\"GettyImages-182222423.jpg\" src=\"https:\/\/pocket-syndicated-images.s3.amazonaws.com\/5e6fa464c4b5c.jpg\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Photo from webphotographeer \/ Getty Images<\/em>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Steak knives, scissors, writing desks, and power tools: If you bring any of these things up around someone and they cringe, they either have a bizarre story to tell or they\u2019re just left-handed, and, like 15 percent of the population, live in a world that\u2019s <a href=\"https:\/\/www.inverse.com\/article\/17601-left-handed-iphone-users-rejoice-apple-patents-special-southpaw-mode\">not designed for them<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But handedness goes deeper than how you like to hold a pen. A dive into the <a href=\"https:\/\/www.inverse.com\/topic\/genetics\">genetics<\/a> of handedness reveals that southpaws have quite a few other things in common, as well. But before that, it\u2019s important to understand where handedness comes from.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Where Does Handedness Come From?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">It used to be thought that lefties came to be as a result of a mother being stressed during pregnancy, but a more scientifically valid explanation has traced handedness to specific genes. Geneticists debated for years over whether the genes responsible for handedness were spread throughout our DNA or whether it was just one gene; there seemed to be no clear pattern.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now, it seems to be accepted that <a href=\"https:\/\/www.inverse.com\/article\/28350-hand-preference-spine-bra\">one gene does most of the work<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But even so, it\u2019s still difficult to predict whether a child will be right or left-handed. Because we receive genetic information from both parents, there\u2019s a chance it could go either way, even if mom and pop are both lefties themselves.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">People who have one variant of the gene in question will always be born right-handed. The other, less common variant is <a href=\"https:\/\/www.scientificamerican.com\/article\/what-causes-some-people-t\/\" target=\"_blank\" rel=\"noreferrer noopener\">left up to chance<\/a>, so babies with the \u201crandom\u201d gene will still have a 50-50 chance of being a righty anyway. This is why most people end up right-handed and some sets of identical twins have opposite dominant hands.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Do We Know About Lefty Genetics?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">It seems like that handedness gene, or at least others that are closely associated with it, are responsible for quite a lot. For example, lefties have been shown to have higher rates of <a href=\"https:\/\/www.inverse.com\/topic\/diseases\">diseases<\/a>, like <a href=\"http:\/\/www.anythinglefthanded.co.uk\/research\/left-handed-research-current.html#fighters\" target=\"_blank\" rel=\"noreferrer noopener\">inflammatory bowel disease<\/a> or Crohn\u2019s disease.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Most studies on handedness and potential health risks only show that there\u2019s a link between the two, not any direct cause-and-effect relationship. But even if the exact cause of these diseases remains unknown, you definitely can\u2019t blame it on the struggle with right-handed silverware.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Does a Lefty\u2019s Brain Look Like?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Many of the notable differences between the brains of righties and lefties remain undiscovered, as lefties are often left out of neuroscientific research, because those exact differences can come across as noise in a given study\u2019s <a href=\"https:\/\/www.inverse.com\/topic\/data\">data<\/a>. Despite a <a href=\"https:\/\/www.nature.com\/nrn\/journal\/v15\/n3\/full\/nrn3679.html\" target=\"_blank\" rel=\"noreferrer noopener\">2014 plea to start studying lefties<\/a> more extensively, little progress has been made. Meanwhile, we know all about how to create mutant left-handed plants. How\u2019s that for scientific priorities?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But we <em>do<\/em> know some things. Notably, the brains of lefties tend to use broader swaths of the cortex for different tasks. While righties use just one of their brain\u2019s hemispheres to remember specific events or process language, these brain functions are spread out across both hemispheres in lefties.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This may make left-handed people <a href=\"http:\/\/www.the-scientist.com\/?articles.view%2FarticleNo%2F44088%2Ftitle%2FLefties--Language--and-Lateralization%2F=\" target=\"_blank\" rel=\"noreferrer noopener\">more resilient to strokes<\/a> or other conditions that damage specific brain regions. If a righty has the small part of their brain responsible for language taken out by a stroke, then that\u2019s that. But because lefties use more of their brain for these tasks, it\u2019s like they have a built-in backup. This widespread brain activation may make southpaws more susceptible to conditions like ADHD and schizophrenia, in which unregulated, heightened activity across multiple regions of the brain causes problems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That\u2019s still a big improvement from previous theories that left-handed people had shorter lifespans linked to increased emotional problems during childhood. But these theories have never found a foothold, getting debunked time and again.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">It\u2019s Not Always About Biology<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Some of the differences between righties and lefties are <a href=\"https:\/\/www.inverse.com\/article\/32603-left-hand-right-hemisphere-brain-persuasion\">more sociological than biological<\/a>. For example, lefties are commonly cited as better fighters. Scientific attempts to correlate left-handedness with a violent predisposition have always fallen short, and it seems like the advantage comes from an element of surprise since lefties are a perpetual minority. This is why lefties are commonly seen as advantaged in head-to-head or combat sports like boxing, tennis, and fencing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">While the science trickles in, it\u2019s important to remember that many of these neurological differences between righties and lefties are minimal, and for the most part you won\u2019t see too much of a difference between people, unless you count some awkwardness when you go for a handshake, or maybe a bumped elbow or two at the dinner table. <em>Dan Robitzski is a neuroscientist-turned-journalist based in New York. His freelance work has appeared in Scientific American.<\/em><\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n","protected":false},"excerpt":{"rendered":"<p>Dan Robitzski Photo from webphotographeer \/ Getty Images. Steak knives, scissors, writing desks, and power tools: If you bring any of these things up around someone and they cringe, they either have a bizarre story to tell or they\u2019re just left-handed, and, like 15 percent of the population, live in a world that\u2019s not designed<\/p>\n<div class=\"more-link\">\n\t\t\t\t <a href=\"https:\/\/fitadelphia.com\/index.php\/2020\/10\/08\/the-unique-science-of-left-handedness\/\" class=\"theme-btn theme-btn-line hvr-bounce-to-right\">Read more<\/a>\n\t\t\t<\/div>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[206],"tags":[209],"class_list":["post-2543","post","type-post","status-publish","format-standard","hentry","category-brain-function","tag-lefties"],"_links":{"self":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts\/2543","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/comments?post=2543"}],"version-history":[{"count":1,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts\/2543\/revisions"}],"predecessor-version":[{"id":2544,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts\/2543\/revisions\/2544"}],"wp:attachment":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/media?parent=2543"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/categories?post=2543"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/tags?post=2543"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}