Why do young children suck their thumbs?

Shari Green
Dental Hygiene Specialist

Thumb sucking starts out as a natural process, often prior to birth. Thumb and finger sucking is a way in which infants self-soothe, and a means by which nature prepares newborns to explore their world, and seek nourishment. But, as time goes on the habit can persist, often into early childhood. Many young children associate the sucking behavior with positive feelings that are actually biochemically based. The opiate reward system is activated during the sucking process, initially as a means of soothing and comfort, and later this reward system can be easily activated after during times of upset, boredom, or distress. They are only a thumb's distance away. Young children may use their thumb to wind down after a hard day or fall asleep at night, often as a response to this cycle of reward and reinforcement. In addition, thumb and finger sucking is a subconscious habit, and most children do not even realize that their finger has entered their mouth until it is brought to their consciousness by a well-meaning family member. This is what makes thumb sucking such a challenging habit to eliminate. Children often are not aware they are sucking, and are being physiologically rewarded for participation.

Dr. Heather Wittenberg, PhD
Psychology Specialist

Young children have such little control in their worlds. They’re physically small. They aren’t very coordinated. They’re not allowed to do a ton of cool-looking stuff. Their bodies and minds develop so quickly from day to day, they have no idea what they can (or can’t) accomplish at any particular time. And at any moment, they’re liable to get picked up without warning and taken somewhere they don’t wanna go. Their independence is developing, and yet it’s often thwarted. You can’t blame them for trying to establish some sense of power and control in their life.

That’s why they need self-soothing strategies; funky little habits that help them feel better about the lack of control and chaos they experience in daily life. These self-soothing strategies are also selected partly to aggravate us, as parents. It’s your kid’s way of saying, “You may be able to have 90% control of me, but this 10% is all about me.” The fact that it annoys you may be what makes it so powerful to your daughter. It’s her way of saying, “I finally have some control here! I can get Mommy really bananas about this finger sucking thing!”

As a child psychologist, I’m not usually worried about the young kids who have developed weird, annoying self-soothing strategies. I do worry about the kids who are too compliant and too easy, at this age. Their budding sense of independence needs to be appreciated and given room to grow.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.