For infants, sucking on either their own fingers or a pacifier has several benefits. In the first six months of life, sucking helps infants soothe themselves when they are bored or hungry, and actually has pain-relieving qualities. Infants who suck their thumb or a pacifier overnight also have a lower risk of suffering sudden infant death syndrome (SIDS), also known as “cot death.” There are still risks associated with sucking in this age category, namely early breast weaning, but the benefits of sucking outweigh this risk for infants.
The benefits of thumb sucking end once a child reaches six months of age. Sucking behaviour between six months and two years of age is linked to increased infections, most notably ear infections (a.k.a. otitis media). Because of this, the American Academy of Pediatrics (AAP) and the American Association of Family Physicians (AAFP) both recommend reducing or stopping sucking at six months old, and the Institute for Clinical Systems Improvement (ICSI) recommends stopping sucking altogether by 10 months of age. If a child continues to suck his thumb or pacifier after two years of age, significant physical consequences can result, including malformation of the teeth and jaw.
Summary of age guidelines: Finger or pacifier sucking is beneficial for infants under six months old. By six months, sucking behaviour should begin to be discouraged, with a full stop recommended by 10 months. The persistence of sucking after two years of age is associated with significant physical consequences (See Oral Myofunctional Disorder under Services).
Katherine Christ, honours Linguistics Head of Research at Simone Friedman Speech-Language Services
Source: Sexton, S., & Natale, R. (2009). Risks and benefits of pacifiers. American Family Physician 79, (8), 681-685.
