{"id":49741,"date":"2020-12-23T09:43:56","date_gmt":"2020-12-23T14:43:56","guid":{"rendered":"https:\/\/languagelog.ldc.upenn.edu\/nll\/?p=49741"},"modified":"2020-12-23T10:12:00","modified_gmt":"2020-12-23T15:12:00","slug":"genes-and-tone-languages-yet-again","status":"publish","type":"post","link":"https:\/\/languagelog.ldc.upenn.edu\/nll\/?p=49741","title":{"rendered":"Genes and tone languages, yet again"},"content":{"rendered":"

Below is a guest post by Bob Ladd<\/a>.<\/p>\n

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Long-time readers of Language Log may recall a couple of posts from 2007 (here<\/a> and here<\/a>) about a possible link between population genetics and tone languages. That year, Dan Dediu and I published a paper in PNAS<\/em><\/a> showing that there\u2019s a significant geographical correlation between the distribution of tone languages and the distribution of older and newer variants (alleles) of two genes known to be involved in brain development, ASPM<\/em> and Microcephalin 1<\/em>.\u00a0 For ASPM <\/em>in the Old World (where tone languages are found predominantly in sub-Saharan Africa and Southeast Asia), you can eyeball the correlation on the map below: the lighter the dot, the rarer the new variant of the gene.\u00a0 Our PNAS <\/em>paper put this eyeballing on a reasonably sound statistical basis.<\/p>\n

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However, all we did was demonstrate a correlation, and lots of people were ready to remind us that \u201ccorrelation is not causation\u201d. There were also plenty of other people who wanted nothing to do with the idea that genetic differences might have anything to do with language typology at all.\u00a0 There were more than a few interestingly awkward conversational silences when I attended the ICPhS meeting in Saarbr\u00fccken later that summer.<\/p>\n

But the idea that small biological variations might have an influence on language keeps surfacing.\u00a0 For example, a much more recent Language Log post\u00a0 (here<\/a>) discussed the suggestion that changes in dentition (possibly due to the spread of agriculture) may have led to an increase in the use of labiodental sounds in the languages of the world.\u00a0 And coming back to tone languages, a few months ago Patrick Wong and his colleagues in Hong Kong published direct experimental evidence that individual genetic makeup with regard to ASPM <\/em>has an effect on the way individuals deal with linguistic tone.<\/p>\n

Their study was based on more than 400 native speakers of Cantonese, who were genotyped for ASPM <\/em>and Microcephalin 1 <\/em>and for several other genes (such as FOXP2<\/em> and CNTNAP<\/em>) which have previously been shown to have some involvement with language.\u00a0 The speakers performed a simple-seeming task that required them to discriminate Cantonese pseudo-words that differed only in lexical tone. Wong and his colleagues found that carriers of the new allele of ASPM <\/em>had worse average performance than those not carrying it. None of the other genes tested (including Microcephalin 1<\/em>) had any effect on the outcome.\u00a0 (Wong et al., \"ASPM-lexical tone association in speakers of a tone language: Direct evidence for the genetic-biasing hypothesis of language evolution<\/a>\", Science Advances<\/em> 2020.)<\/p>\n

Whether you were interested or dismissive when Dediu and I started speculating about genes and tone languages back in 2007, Wong\u2019s results are harder to ignore than a mere correlation.\u00a0 We\u2019ve recently posted a new paper<\/a> to PsyArXiv putting his study in the context of our original proposal. We think his work is a potentially important step in our developing understanding of the biological bases of human language.<\/p>\n\n

Above is a guest post by Bob Ladd.<\/p>\n

For a more quantitative graphical summary of the results of Wong et al. 2020<\/a>, see their Figure 1:<\/p>\n

<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Below is a guest post by Bob Ladd. Long-time readers of Language Log may recall a couple of posts from 2007 (here and here) about a possible link between population genetics and tone languages. That year, Dan Dediu and I published a paper in PNAS showing that there\u2019s a significant geographical correlation between the distribution […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[209],"tags":[],"class_list":["post-49741","post","type-post","status-publish","format-standard","hentry","category-biology-of-language"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=\/wp\/v2\/posts\/49741","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=49741"}],"version-history":[{"count":7,"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=\/wp\/v2\/posts\/49741\/revisions"}],"predecessor-version":[{"id":49748,"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=\/wp\/v2\/posts\/49741\/revisions\/49748"}],"wp:attachment":[{"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=49741"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=49741"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/languagelog.ldc.upenn.edu\/nll\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=49741"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}