{"id":72713,"date":"2012-07-19T23:33:35","date_gmt":"2012-07-20T07:33:35","guid":{"rendered":"http:\/\/blogs.discovermagazine.com\/gnxp\/?p=17405"},"modified":"2012-07-19T23:33:35","modified_gmt":"2012-07-20T07:33:35","slug":"cousin-marriage-can-reduce-i-q-a-lot","status":"publish","type":"post","link":"https:\/\/www.razib.com\/wordpress\/2012\/07\/19\/cousin-marriage-can-reduce-i-q-a-lot\/","title":{"rendered":"Cousin marriage can reduce I.Q. a lot"},"content":{"rendered":"<p>In light of <a href=\"http:\/\/blogs.discovermagazine.com\/gnxp\/2012\/07\/inbred-shorter-people\/\">the previous post<\/a> I was curious about the literature on inbreeding depression of IQ. A literature search led me to conclude two things:<\/p>\n<p>&#8211; This is not a sexy field. A lot of the results are <em>old<\/em>.<\/p>\n<p>&#8211; The range in depression for first cousin marriages seems to be on the order of 2.5 to 10 IQ points. In other words ~0.15 to ~0.65 standard deviation units of decline in intelligence.<\/p>\n<p>The most extreme case was this paper from 1993, <a href=\"http:\/\/www.springerlink.com\/content\/f608480457n22667\/\">Inbreeding depression and intelligence quotient among north Indian children<\/a>. The authors compared the children of first cousin marriages, and non-bred in individuals, from a sample of Muslims in Uttar Pradesh of comparable socioeconomic status (though the authors note that inbreeding has a positive correlation with socioeconomic status in this community). A table with results speaks for itself:<\/p>\n<p>\n<a href=\"http:\/\/blogs.discovermagazine.com\/gnxp\/files\/2012\/07\/inbred.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-17406\" title=\"inbred\" src=\"http:\/\/blogs.discovermagazine.com\/gnxp\/files\/2012\/07\/inbred.jpg\" alt=\"\" width=\"596\" height=\"473\" \/><\/a><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/feeds.feedburner.com\/~r\/GeneExpressionBlog\/~4\/5o563TAXKDY\" height=\"1\" width=\"1\"\/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In light of the previous post I was curious about the literature on inbreeding depression of IQ. A literature search led me to conclude two things:<br \/>\n&#8211; This is not a sexy field. A lot of the results are old.<br \/>\n&#8211; The range in depression for first cousin mar&#8230;<\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[498,17],"tags":[],"class_list":["post-72713","post","type-post","status-publish","format-standard","hentry","category-i-q","category-psychology"],"_links":{"self":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts\/72713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/comments?post=72713"}],"version-history":[{"count":5,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts\/72713\/revisions"}],"predecessor-version":[{"id":72775,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts\/72713\/revisions\/72775"}],"wp:attachment":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/media?parent=72713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/categories?post=72713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/tags?post=72713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}