Dawn Field, author of Biocode, looks at the science behind why some people are predisposed to dislike the sound of other people chewing:
Like a quality antique, the beauty of a genome is that it only accrues value as time wears on. Consumer genetics company 23andMe has just sent out one million emails; they genotyped their one millionth customer DNA sample in June 2015. This means there is now officially a one million person genomic data set. Each recipient was congratulated in the email for being part of this historic turning point and given a “number”. I imagine it would be fun to be either number one or number one million for different reasons.
All one million customers gave away their DNA in return for getting personal profiles. Yet, the data are being used in many ways, most notably to explore therapies for Parkinson’s disease. These studies now also include exploring why about 20% of 23andMe customers describe themselves as "filled with rage" by the sound of other people chewing (or nail clipping, etc). Amazingly it turns out this trait has a genetic basis. You have a 1.2 times higher odds of having misophonia, otherwise known as a "hatred of sound", if you have GG at genetic marker rs2937573 found near TENM2, a gene thought to play a role in the brain.