The childhood habit doesn’t go away for everyone — and neither does the shame around it

Eric, a 45-year-old advertising executive with a major U.S. agency, was being upbraided by an angry client displeased by the lousy performance of a recent campaign when the conference room suddenly fell silent, and Eric realized all eyes were on him.

“Dude, what are you doing?” his colleague whispered.

It was at that moment that Eric realized he was sucking his thumb.

“Oh, sorry,” Eric said with a nervous laugh, withdrawing his thumb to a loud shlop. “I’ve just got this piece of loose skin on my thumb. I’ll take care of it later.”

Eric, of course, was lying. In truth, he’s an adult thumbsucker, who takes to the habit whenever he’s under stress — like when he’s being berated by an angry client.

Making matters worse, his speech had become affected by an anterior open bite, i.e., a gap between the upper and lower front teeth when the jaw is closed. An orthodontist referred him to Jennifer Connelly, a speech pathologist who recalls Eric being a nervous wreck when he arrived at her office complaining of an overbite that was ruining his oral presentations. Connelly noticed some pruning, (i.e., wrinkled fingertips), on Eric’s left thumb and asked if there were any oral habits she should know about. “I knew immediately he was a thumbsucker,” she tells me. Eric, however, would only admit that he sometimes bit his thumb to remove dead skin.

Pruning

“I see,” Connelly replied, changing course. “I sucked my thumb until I was eight and thoroughly enjoyed it.” Eric’s face loosened as she went on to explain how difficult she remembered it being when her parents made her stop. Over the next 45 minutes, he became increasingly more comfortable and eventually confessed that he’d been sucking his thumb since childhood. Now, though, his thumb ended up in his mouth without even noticing.

“It’s telling that his first admission was ‘I bite my thumb,’” Connelly notes, “since I suppose that’s considered manlier than sucking it.” Connelly’s speciality is Dental Facial Myofunctional Therapy, i.e., studying how soft tissue affects hard tissue in the mouth. She says many of her patients present non-nutritive sucking habits like thumbsucking, which contrary to popular belief, isn’t a sign of immaturity. “We all have behaviors to relieve stress and boredom,” she says. “I’d rather have someone suck their thumb than down 10 martinis and smoke a pack of cigarettes. In comparison, it’s a relatively harmless habit.” (Aside from the perma-colds her clients typically suffer from: “There’s nothing dirtier than the fingers,” she explains.)

Thumbsucking is, in fact, a natural reflex developed in utero, according to Susan M. Heitler, a child psychologist in Denver, and author of the children’s book David Decides About Thumbsucking. If we didn’t have it, we’d die, she tells me, since babies have to be able to suck on their mother’s breast to get milk. “Sucking is a rhythmic, quieting activity,” Heitler explains. “When a baby or toddler is upset and sticks their thumb in their mouth, the breathing evens out and the heart rate slows down. It’s the earliest form of self-soothing. Adults are drawn to exactly the same benefits.”

Most people, however, stop the habit by age five or six, often due to direct intervention from their parents. As Hashimatze, a 25-year-old redditor remembers, “My relatives attempted to scare me when I was a kid by saying, ‘If you don’t stop sucking your thumb, one day it’s going to split in two!’”

“That’s bad,” replies Andy, a 42-year-old in Germany. “But telling a child that both his thumbs will be cut off if he doesn’t stop sucking it is much worse. That’s what happened to me when I was a boy.” As he explains, his parents read him a book called Struwwelpeter about naughty children and the punishment they received for their bad behavior. In one story — “Die Geschichte vom Daumenlutscher,” or “The Story of Little Suck-a-Thumb” — a boy is warned by his mother not to suck his thumb while she’s out, otherwise “The Scissorman” would come and cut off both his thumbs. Naturally, the boy ignores the warning and sucks his thumb anyway. Sure enough, The Scissorman arrives and gets to cutting. When mom comes home to find her thumbless son standing in the kitchen, she just crosses her arms and says, “I told you so.”

As for statistics on how many adults maintain the infantile habit, Connelly says studies are skewed since so few people admit to doing something society connects with shame. “People think, ‘Only babies suck their thumb.’ Even some of my colleagues who aren’t educated in this area of expertise will say, ‘What, an adult man sucking his thumb?’”

That doesn’t accurately describe Harvey Miller, a 68-year-old thumbsucker in New York who proselytizes the way of the thumb. As the New Yorker asks me on on the phone, where else can you find a drug- and calorie-free legal habit that’s instantly calming, quiet, convenient, non-intrusive and aids in both sleep and concentration? And so, since 1999, Miller has been the webmaster of thumbsuckingadults.com, where he serves as a de facto consigliere for what he describes as a “close-knit community of more than 1,700 adult thumbsuckers.” (A testament to their closeness: Three couples have met in the forums and eventually married.)

“My motivation is to help people,” he explains. “It’s amazing to me how much suffering people have related to this habit.” For example, one woman reached out to Miller after having kept her thumbsucking a secret from her husband of 15 years. After seven months of online psychotherapy from Miller and the community, she was finally able to come clean.

Miller estimates that between 3 and 7 percent of the U.S. adult population sucks their thumbs, figures he’s derived from a series of highly unscientific surveys he’s taken over the years. After fielding many of the same questions over and over again — i.e., Why do we suck our thumbs?; why haven’t I stopped like so many others have?; are there any “thumbsuckers anonymous” support groups?; I use a blankie while sucking, what’s that about?; will sucking my thumb in front of my children be harmful? — he made a general FAQ section. When members asked for photographs, he made a photos section. Meanwhile, concerns about calluses forming on thumbs led to a callus section, and those relating to open bites led to dental section — and so on and so forth.

“I receive so many emails from men, some going away to college, others going into the military. They ask, ‘What the hell am I going to do in the Marines if I’m caught sucking my thumb?’ I urge them to be confident about doing it so that it won’t allow people to take advantage of what they perceive to be a weakness.”

“Harvey is a legend in the community because for many of us, his website and advocacy was the first indication that we were part of a larger group,” explains Connor, a 43-year-old in upstate New York and moderator of r/thumbsucking, who tells me he’s sucked his thumb since infancy and considers it a major component of his identity. Connor (like with Eric, a pseudonym) scoffs at the notion that his habit is unsanitary. “Thumbsuckers have the strictest hand-washing routines of any other population,” he contends. “We’re very aware of where we’re placing our hands and what we’re touching. Most of us have one specific thumb we suck, and use the other hand for grasping objects, opening doors, etc. We do this for our own protection as well, as we certainly don’t want to be getting any of your nasty germs in our mouths.”

More generally, he says it’s “a personal private habit” that thumbsuckers are very sensitive about, so if you see someone sucking their thumb it’s best to leave them alone. “It’s not a big deal,” he insists. “It’s not hurting you, so leave us alone.”

But is it hurting their relationships? Connor’s partner recently caught him mid-suck, and he quickly withdrew his thumb, defensively. She laughed and said he didn’t need to hide since she sees him do it in his sleep all the time. Now he sucks his thumb while relaxing with her watching TV or listening to audiobooks.

Miller takes romantic thumbsucking a step further. “I had a girlfriend who, like me, sucked her thumb,” he recalls. “We’d occasionally suck each other’s thumbs. It felt quite intimate, and we each learned the way to put our thumb in each other’s mouths so it felt more ‘natural’ as each thumbsucker has their own method and preference.”

And yet fears about romantic partners’ reactions abound on r/thumbsucking. “How do I tell my girlfriend I suck my thumb?” asks 18-year-old Dustydexx. “I’ve been thumb sucking all my life. I can’t sleep without it, and it’s become a habit to calm my anxiety through a traumatizing childhood.” At this point, he’s accepted there’s nothing he can do to change it, and if forced to choose between a woman and his thumb, he’ll be forced to pick the latter. “If she doesn’t accept it, I’ll know it wasn’t meant to be,” he adds. “It’s truly my darkest secret. What a lame-ass dark secret.”

Dusty’s fears, however, are warranted if you ask my Facebook friends, who each classify thumbsucking as a “dealbreaker” in a relationship. “I’d have a difficult time seeing him as a sexual partner/equal,” says Tracey, a middle-aged linguist professor in Milwaukee. “Even if I could get beyond the infantile habit, I’d see it as a signifier of other unresolved issues. Maybe it has to do with me being a mom — a thumbsucker is someone who I’d view as needing to take care of rather than engage with in an adult way.” Likewise, Stephen, a 54-year-old designer in L.A., says a relationship with a thumbsucker wouldn’t get past the first date since it screams of anxiety and insecurity. “I’d assume the person would be coming with unboxed baggage,” he tells me.

Hussain, a 27-year-old grad student in Australia, sums it up nicely. He used to suck his thumb but was able to break the habit thanks to wearing gloves every night for a year whenever he went to bed. “People try to defend, it but that’s just their addiction tricking them,” he says. “I’d suggest taking a picture of themselves sucking their thumb and look at it for a minute. Is that really the person you want to be?”