それたぶん遺伝子的にできない人がいると思うが

　それ⇒さくらんぼの軸を舌で結ぶ方法 : ライフハッカー［日本版］, 仕事も生活も上手くこなすライフハック情報満載のブログ・メディア
　Tongue rollingと同じじゃないかと。
　ところが。
　⇒Tongue rolling : Tongue - Wikipedia, the free encyclopedia

There is little laboratory evidence, though, for the common belief that tongue rolling is inheritable and dominant. A 1975 twin study found that identical twins (who share all of their genes) were no more likely than fraternal twins (who share an average of half) to both have the same phenotype for tongue rolling.[12][13]