{"id":201,"date":"2005-08-26T13:31:51","date_gmt":"2005-08-26T18:31:51","guid":{"rendered":"\/?p=201"},"modified":"2005-08-26T13:40:01","modified_gmt":"2005-08-26T18:40:01","slug":"out-like-flynn","status":"publish","type":"post","link":"http:\/\/esr.ibiblio.org\/?p=201","title":{"rendered":"Out like Flynn"},"content":{"rendered":"<p>Renowned pychometrician Charles Murray has given us, in <a href=\"http:\/\/www.commentarymagazine.com\/production\/files\/murray0905.html\">The<br \/>\nInequality Taboo<\/a>, a concise summary of the most current science on<br \/>\ngroup differences in IQ and other measures of capability.  Most of it<br \/>\nis not surprising to anybody who has been following the actual science<br \/>\nrather than press accounts severely distorted by the demands of<br \/>\npolitical correctness.<\/p>\n<p>There is some new information here, however, and perhaps the most<br \/>\ninteresting bit is that turns out to be much less to the Flynn effect<br \/>\nthan meets the eye.  The Flynn effect is the long-term rise in average<br \/>\nIQ scores recorded since IQ began to be measured in the early 20th<br \/>\ncentury.  Advocates of the view that IQ is unimportant or meaningless<br \/>\nhave seized on the Flynn effect to argue that IQ is either (a) a<br \/>\nstatistical artifact, or (b) almost entirely environmentally driven<br \/>\n(and thus can presumptively be increased by correct social<br \/>\npolicy).<\/p>\n<p>Murray&#8217;s news is that the Flynn effect is not being driven by a<br \/>\nrise in average g, the measure of general mental ability that accounts<br \/>\nfor over 50% of variance in almost all kinds of mental aptitude tests.<br \/>\nSince Spearman discovered the &#8216;g&#8217; statistic, almost all psychometricians<br \/>\nhave accepted that IQ is interesting precisely because it is a good<br \/>\napproxmation of g.  Thus, the Flynn effect is basically a mirage &mdash;<br \/>\nit&#8217;s taking place in the noise, not the signal.<\/p>\n<p>I&#8217;m not entirely sure what this means yet, and I don&#8217;t believe<br \/>\nMurray or other psychometricians have gotten to the bottom of it<br \/>\neither.  But at minimum, it&#8217;s very suggestive that IQ differences are<br \/>\neither genetic or driven by environmental factors over which we have<br \/>\nlittle control.  Spearman&#8217;s g, in particular, is notoriously<br \/>\nintractable.  It is highly heritable according to separated-twin<br \/>\nstudies. And while there is good evidence that it can be lowered from<br \/>\nits &#8216;natural&#8217; genetic level by unfavorable environment (such as poor<br \/>\nchildhood nutrition), it apparently can&#8217;t be raised by a favorable<br \/>\none.<\/p>\n<p>Indeed, Murray reports in a footnote evidence from a study in<br \/>\nDenmark that the Flynn effect has leveled off since the early 1990s.<br \/>\nThus, it may be that we have already maxed out the effects of wealth<br \/>\nand better nutrition on the both the g and non-g components of IQ that<br \/>\nwe <em>can<\/em> manipulate.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Renowned pychometrician Charles Murray has given us, in The Inequality Taboo, a concise summary of the most current science on group differences in IQ and other measures of capability. Most of it is not surprising to anybody who has been following the actual science rather than press accounts severely distorted by the demands of political&hellip; <a class=\"more-link\" href=\"http:\/\/esr.ibiblio.org\/?p=201\">Continue reading <span class=\"screen-reader-text\">Out like Flynn<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-201","post","type-post","status-publish","format-standard","hentry","category-science","entry"],"_links":{"self":[{"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=\/wp\/v2\/posts\/201","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=201"}],"version-history":[{"count":0,"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=\/wp\/v2\/posts\/201\/revisions"}],"wp:attachment":[{"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=201"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=201"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/esr.ibiblio.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=201"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}