Thumb sucking is a perfectly normal habit for babies and young children, but while most grow out of it by age five, some never do. You’ve probably never seen an adult suck their thumb, but that’s only because the vast majority of adult thumb-suckers avoid doing it in public for fear of being laughed at or labeled as “weirdos”. Some experts believe that adult thumb sucking is quite common, with around 1 in 10 adults secretly engaging in the habit for comfort.

Thumb sucking is said to start in the uterus, even before we come into this world. It is considered a comforting gesture that mimics the endorphin rush babies get when breastfeeding, and is most common in children coping with mild anxiety. The same is true for adult thumb-suckers. While they are no longer breastfed, sucking their thumb is an effective way of dealing with anxiety or just completely relaxing at bedtime. Some have relied on their thumb to sooth them for as long as they can remember, and it has just become a normal part of everyday life.

Photo: YouTube screengrab

Most adult thumb-suckers would do it constantly if they could, but the fear of being judged or misunderstood by society is too high. They will control themselves in public, but as soon as they are in the comfort of their own home, or their car, they’ll stick their thumb in their mouth, wrap the index finger around the bridge of their nose for support, and enjoy their life-long habit.

“I think that thumb sucking fills a void, yeah, definitely completes the circuit” says 65-year-old Harvey Miller, an adult thumb-sucker from East Meadow, New York. He’s been doing it all his life, while watching TV, reading, driving, and before going to sleep. To him, it’s a comfort zone, and he doesn’t want to stop. What he would like is for people to be able to accept thumb sucking as the free, legal, drug-free, quiet habit that it is, instead of seeing it as a joke or just plain weird.

Photo: Thumbsucker movie screengrab

“I would like to be able to suck my thumb in public, I just, I’m not there,” Harvey says. “I don’t think I could stand the misinterpretations and the attention it would get.”

Harvey is definitely not alone. “Adult thumb sucking is actually quite common. Around 1 in 10 adults do it, more women than men. In fact, double the number of women compared to men and even some celebrities like Rihanna have been spotted doing it,” says counselling psychologist Chris Hart. There is a worldwide community of them, and, until not too long ago, they even had a website. It appears to be down now, though, for reasons I can only speculate on.

Photo: YouTube screengrab

Harry Oloo, a Nairobi-based banker in his late 30s, tried to quit thumb sucking several times throughout his life, but always found himself coming back to it. It was there for him in school when he got anxious about exams, and now, it’s still there now, when he goes to sleep at night. He was afraid that his wife might find it disturbing, but she apparently thinks it’s cute.

“This is a habit that I developed in my childhood. I was often teased about it by my high school classmates as I did it often especially when anxious about exams,” Oloo told SDE Kenia. “They called me ‘Big Baby’. Now as a professional banker, I have learnt to hide it quite well. I don’t do it at work. And I have found that I can control it when it public. However, when I get home and I am settling in for bed, I find my thumb in my mouth. I used to feel embarrassed whenever my wife found me doing it but she doesn’t seem to mind it. She actually says that it is cute.”

A lot of people associate adult thumb sucking with a sexual fetish, but for the vast majority of grown-ups who engage in this habit it’s just a harmless coping mechanism. The only known side-effects are social embarrassment and, in some cases, dental problems. Dr Christopher Ho told Yahoo’s Be Lifestyle that thumb sucking can cause irreparable damage.

“It is best if children have given up the habit by the age of four because prolonged sucking after the permanent teeth have started to erupt (at around five to six years old) can result in dental problems such as an open bite, ‘buck teeth’, poorly developed lower jaw and narrow palate,” Dr. Ho says. “As an adult thumb sucking leads to a narrow smile and often an open bite leading to difficulty biting certain foods.”