Adult thumb sucking is more common that people think, but it is a secret habit. of them, and, until not too long ago, they even had a website.
The definitive site for adult thumb suckers. Articles and Photos of adult thumb suckers.
In addition to WebMD, there's also a website dedicated to thumb sucking adults, with some facts and a FAQ section. Though it's citing statistics.
Polls done on the website suggested that slightly fewer than half of their adult thumb-suckers use their left thumb, with the slight majority using.
While thumb sucking isn't an issue in babies or young children, adult thumb sucking may be embarrassing and in some cases may pose oral health problems .