--- title: Study: IQ Scores Are Falling Due to Environmental Factors description: IQ scores are on a decline, reversing a trend that saw scores rising at a steady rate during the 20th century, according to a new study. canonical: https://time.com/5311672/iq-scores-decline-environment/ author: Mahita Gajanan article:opinion: false article:content_tier: free article:published_time: 2018-06-13T22:11:59.000Z article:modified_time: 2026-02-23T20:34:01.374Z article:section: Science og:title: IQ Scores Are Falling Due to Environmental Factors, Study Finds og:description: 'It's not that dumb people are having more kids than smart people, to put it crudely' og:url: https://time.com/5311672/iq-scores-decline-environment/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt2f132f1535df74ad/69893303db2987665325feac/iq-test-decline.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Setting the page on fire with some hard work og:type: article twitter:card: summary_large_image twitter:title: IQ Scores Are Falling Due to Environmental Factors, Study Finds twitter:description: 'It's not that dumb people are having more kids than smart people, to put it crudely' twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt2f132f1535df74ad/69893303db2987665325feac/iq-test-decline.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # IQ Scores Are Falling Due to Environmental Factors, Study Finds by [Mahita Gajanan](https://time.com/author/mahita-gajanan/) ## Mahita Gajanan Gajanan is an editor at TIME. Jun 13, 2018 10:11 PM UTC  Closeup shot of a young man writing on a note pad Closeup shot of a young man writing on a note padPeopleImages—Getty Images by [Mahita Gajanan](https://time.com/author/mahita-gajanan/) ## Mahita Gajanan Gajanan is an editor at TIME. Jun 13, 2018 10:11 PM UTC IQ scores are on a decline, reversing a trend that saw scores rising at a steady rate during the 20th century, according to a new study. Researchers from the Ragnar Frisch Centre for Economic Research in Norway studied the IQ scores of about 730,000 Norwegian men born between 1962 and 1991\. They found that scores grew by nearly three percentage points every decade for people born between 1962 and 1975\. But among those born after 1975, scores fell. The cause of the IQ decline is due to environmental factors, and not genetics, said Ole Rogeburg, a senior research fellow at Ragnar Frisch Centre and co-author of the [study on IQ scores](http://www.pnas.org/content/early/2018/06/05/1718793115), published in the Proceedings of the National Academy of Sciences journal. “It’s not that dumb people are having more kids than smart people, to put it crudely,” Rogeburg told CNN. “It’s something to do with the environment, because we’re seeing the same differences within families.” Environmental factors include differences in the way young people are educated, increases in time spent online, changes in nutrition and less reading overall. The downward trend is a reversal of the Flynn effect, a term that describes the vast improvement of IQ scores in many parts of the world throughout the 20th century. According to the study, the Flynn effect peaked in the mid-1970s and has declined in the decades since. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/5311672/iq-scores-decline-environment/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/5311672/iq-scores-decline-environment/"},"headline":"IQ Scores Are Falling Due to Environmental Factors, Study Finds","datePublished":"2018-06-13T22:11:59.000Z","dateModified":"2026-02-23T20:34:01.374Z","description":"Researchers found a steady decline in IQ scores over the past few decades","url":"https://time.com/5311672/iq-scores-decline-environment/","keywords":[],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt2f132f1535df74ad/69893303db2987665325feac/iq-test-decline.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Mahita Gajanan","jobTitle":"Gajanan is an editor at TIME.","url":"https://time.com/author/mahita-gajanan/"}],"articleSection":"Science","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt2f132f1535df74ad/69893303db2987665325feac/iq-test-decline.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Setting the page on fire with some hard work","caption":"Setting the page on fire with some hard work","creditText":"PeopleImages—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/science/","name":"Science"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/5311672/iq-scores-decline-environment/","name":"IQ Scores Are Falling Due to Environmental Factors, Study Finds"}}]}] ```