> Back in 2007, a large-scale statistical research study by Dan Dediu and D. Robert Ladd, linguists at the University of Edinburgh at the time, found that individuals with specific genotypes of the ASPM and MCPH genes are more likely to speak a tone language. These genes are related to brain growth, and certain genotypes are more likely to be found in populations in sub-Saharan Africa and East and Southeast Asia. Interestingly, languages in these regions are more likely to be tone languages.