Genes may help people learn Chinese
- Genes may help people learn Chinese
- 22:00 28 May 2007
- NewScientist.com news service
- Nora Schultz
All babies can grow up speaking any language, but now researchers have uncovered evidence that genes may in fact play a part in learning so-called "tonal languages", such as Chinese.
Subtle pronunciation differences in tonal languages can radically change the meaning of words, which may be one reason why such languages are so hard to learn for speakers of non-tonal languages like English. So for a non-native Chinese speaker, to enquire after the health of someone’s mother might easily result in a query about the wellbeing of their horse.
And now it appears that there may after all be something in our genes that affects how easily tonal languages can be learned. Such are the findings of Dan Dediu and Robert Ladd of Edinburgh University, UK, who have discovered the first clear correlation between language and genetic variation.
Using statistical analysis, the pair showed that people in regions where non-tonal languages are spoken are more likely to carry different, more recently evolved forms of two brain development genes, ASPM and Microcephalin, than people in tonal regions. Dediu and Ladd accounted for geography and history, and the gene differences remained.
Bernard Crespi, an evolutionary biologist at Simon Fraser University in Burnaby, Canada, says the results "open up a whole new field of
inquiry, that links language evolution with adaptive molecular evolution and brain function."
No genetic advantage
Since both genes function in brain development, Dediu and Ladd propose that they may have subtle effects on the organisation of the cerebral cortex, including the areas that process language.
It is already known that brain anatomy differs between English speakers who are good at learning tonal languages and those that find it harder, says Ladd, who now wants to see whether similar differences can be found between individual carriers of the ASPMand Microcephalin variants.
A remaining puzzle is the role of natural selection. It has been argued that the newer variants of these two genes are positively selected, but so far nobody has been able to show how they might provide a selective advantage.
Dediu and Ladd do not think the genes' link to tonality could be the answer. "There is absolutely no reason to think that non-tonal languages are in any way more fit for purpose than tonal languages," says Ladd. "Chinese society developed advanced technology, politics and philosophy with a tonal language just as successfully as roughly contemporary eastern Mediterranean societies with non-tonal languages."
But Crespi speculates that the lower complexity of non-tonal languages could confer a selective advantage: "Adoption of a simpler language might be 'easier', allowing for faster acquisition of language or other brain functions in early childhood. These ideas could be tested."
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0610848104)