--- description: Today is International Left Handers Day, here's what we know about why some people are left-handed title: Why Are Some People Left-Handed? image: https://static.time.com/v3/assets/bltea6093859af6183b/blte399f885dfcb245b/6988a24bcd1bba64af701f5a/left-hand.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  * [U.S.](/section/us/) ## U.S. Update your preferences in [Account Settings](/account/preferences/) Close * [Genetics](/tag/genetics/) ## Genetics Update your preferences in [Account Settings](/account/preferences/) Close # Why Are People Left-Handed? by [Alexandra Sifferlin](/author/alexandra-sifferlin/) ## Alexandra Sifferlin Update your preferences in [Account Settings](/account/preferences/) Close Aug 13, 2016 2:42 PM CUT  Getty Images by [Alexandra Sifferlin](/author/alexandra-sifferlin/) ## Alexandra Sifferlin Update your preferences in [Account Settings](/account/preferences/) Close Aug 13, 2016 2:42 PM CUT It’s International Left-Handers Day, so it’s time to give left-handers some overdue appreciation. There was once a time (a long time ago), when people believed that being left-handed meant a person was more prone to “dealings with the devil” and that the trait should be corrected, according to the [New York _Times_](http://www.nytimes.com/2011/03/08/health/views/08klass.html "undefined"). Thankfully, the prejudice is gone, but people are still curious—why do some kids grow up left-handed versus right-handed? Numbers suggest that [about 90% of people are right-handed](http://time.com/4094636/left-handed-facts/ "undefined"), and 10% use their left hand predominantly. [Notable left-handers](http://time.com/3107557/top-10-lefties/ "undefined") include President Barack Obama, Bill Gates and Oprah Winfrey. Some researchers believe that being left-handed is at least partially related to genetics, though it’s likely not the full story. One 2013 study, [published in the journal _PLOS Genetics_](http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1003751 "undefined"), identified genes and gene mutations that can influence the development of “left-right asymmetry in the body and brain,” [Smithsonian.com reports](http://www.smithsonianmag.com/science-nature/why-are-some-people-left-handed-6556937/ "undefined"). It’s possible that some of these genes are related to handedness. But some experts say they think genetics is responsible only 25% of the time, and that handedness [may be pretty random](http://time.com/4094636/left-handed-facts/ "undefined"). [As the _Atlantic_ reports](http://www.theatlantic.com/business/archive/2014/12/why-lefties-make-less/383635/ "undefined"), some researchers believe that being left-handed may be a trait that has continued through time because it gives some people an advantage during fighting. While experts are still sorting out the reasons, scientists[ have shown](http://www.ncbi.nlm.nih.gov/pubmed/23485059 "undefined") that there doesn’t appear to by any differences between right and left-handed people when it comes to personality traits like extraversion, agreeableness, conscientiousness, emotionality and openness to experience. While there are advantages to being left-handed, especially when it comes to sports, there’s also the disadvantages (like getting elbowed during dinner). So make sure that left-handed person in your life is having a happy holiday. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4451303/international-left-handers-day-why-are-people-left-handed/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4451303/international-left-handers-day-why-are-people-left-handed/"},"headline":"Why Are People Left-Handed?","datePublished":"2016-08-13T14:42:37.000Z","dateModified":"2026-02-22T23:57:58.525Z","description":"It's International Left-Handers Day","url":"https://time.com/4451303/international-left-handers-day-why-are-people-left-handed/","keywords":["Genetics","holiday"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blte399f885dfcb245b/6988a24bcd1bba64af701f5a/left-hand.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Alexandra Sifferlin","jobTitle":null,"url":"https://time.com/author/alexandra-sifferlin/"}],"articleSection":"U.S.","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blte399f885dfcb245b/6988a24bcd1bba64af701f5a/left-hand.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"A girl drawn picture seriously","caption":"A girl drawn picture seriously","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/us/","name":"U.S."}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/genetics/","name":"Genetics"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4451303/international-left-handers-day-why-are-people-left-handed/","name":"Why Are People Left-Handed?"}}]}] ```