Yes, I've read that paper, and I read 23&Me's blog post on the trait from 2008 (http://blog.23andme.com/23andme-and-you/tackling-tongue-curl...). They both agree in saying that tongue rolling is not a Mendelian trait, and they both agree there appears to be a heritable component which affects several tongue-shaping traits.

I'm asking because the 23&Me reports don't really include the contextual information to appreciate the subtlety of non-Mendelian traits. If people see this and come to the false conclusion, then they're likely to come to similar false conclusions abotu the parts of the report that touch on actual health-related issues.

Sorry to pry, but is it possible you could go back and look at the report and give an indication of how strongly it seems to imply the trait is genetic? Does it include any caveats (without following their links to literature)? Otherwise indicate this trait isn't strongly genetically determined?