There was an interesting article in last weeks Economist that states that native speaker of tonal languages have a genetic differences to those speakers of non-tonal languages.
I’m not sure what use the research is yet - apart from providing a good excuse for me to explain why picking up Mandarin* was so hard - but it is certainly interesting.
I would be interested to see if there are common differences in the language processing areas of the brains also - otherwise I am confused as to what the genetic difference means.
Anyway it is interesting research and I thought I’d make sure any current Mandarin* students could add it their list of reasons why it is so hard to learn, listen and talk tonal languages.
Linguistics | Words in code | Economist.com
*Other tonal languages exist