Can Overuse Of Pacifiers Be Harmful?

by Heidi Green
October 02, 2012

For many parents, pacifiers (a.k.a. “binkies” and “dummies”) are a “must-have” accessory for their baby, but new research raises some red flags about their use—or, perhaps, their overuse. Three experiments conducted by an international team of researchers all came to the same conclusion: Males who use pacifiers regularly in early childhood seem to have some deficits in their emotional maturity.

Emotional development
Previous studies in the fields of psychology and neurology have identified a connection between facial expressiveness and emotion showing how people of all ages tend to instinctively mimic the expressions of those around them, aiding in emotional connection and effective communication. Factors that impede the ability to express (or mimic) emotion can inhibit the ability to feel emotions and to communicate these feelings to others.

In one study, individuals who used Botox (which immobilizes certain facial muscles in the process of eliminating wrinkles) displayed a smaller range of emotions, and had a hard time recognizing emotions that they were inhibited from making when those emotions were shown on others’ faces. Another study, in which participants held a pen between their lips (effectively limiting their use of the muscles around the mouth) showed similar results.

The relationship between facial expressiveness and emotion seems to be three-fold:

1. The face contributes to the feeling. The muscles of your face send signals to your brain to let it know what expression you’re making, which gives the brain information about your feelings. For example, movement of the “smile muscles” around your mouth and eyes lets your brain know you’re feeling happy; movement of “frown muscles” around your brow lets your brain know you’re frustrated or unhappy. (Think “Fake it ‘til you make it.”)
2. Your expressions contribute to others’ expressions. A big part of communication is responsiveness. Our brains are hard-wired to activate “mirror neurons” when we see other people’s actions—including changes in their facial expressions. (Think “Smile, and the world smiles with you.”)
3. Others’ expressions contribute to a sense of connection. By reflecting another person’s expression, you create some part of the feeling in yourself which shows. The person you’re talking with responds positively to that expression; it is one of the ways we share feelings with others. (Think “Like likes like.”)

It is important to note that people are not imitating emotions. Instead, since the reflection is unintentional and instinctive, this is more accurately called mimicry. But what does this all mean for babies—and their parents?

A lot, according to Paula Niedenthal of the University of Wisconsin at Madison, who examined pacifier use during early childhood, a “critical period of emotional development.”

“We can talk to infants, but at least initially they aren’t going to understand what the words mean,” Niedenthal explains. “So the way we communicate with infants is by using the tone of our voices and our facial expressions. … What if [the baby] always had something in [his] mouth that prevented [him] from mimicking and resonating with the facial expression of [others]?”

Niedenthal’s research team explored this question in three trials. In the first, more than 100 6- and 7-year-old children were asked to watch videos of other people’s facial expressions; 47 of them had used a pacifier, according to their parents’ report, and the average length of use was just over 3 years of age. While there was little difference in response among girl participants, boys who had used pacifiers regularly in early childhood were significantly less likely to mimic the expressions they saw.

The second trial involved 167 college students, 92 of whom had used a pacifier during childhood, for an average length of 22 months. The students completed a standard test of perspective-taking, a component of empathy. Males who reported more pacifier use in early childhood demonstrated less empathy than their peers who did not use pacifiers.

The third experiment also involved college students (428), who took a standard test of emotional intelligence; again, pacifier use was related to lower scores.

While the experiments cannot show causality—that pacifier use necessarily caused less mimicry, less empathy, and lower emotional intelligence—“the incredible consistency across the three studies in the pattern of the data” is worth noting. The findings of all three studies are very suggestive that “[t]here’s a detriment for boys with length of pacifier use even outside of any anxiety or attachment issues that may affect emotional development,” Niedenthal explains.

Interestingly, although the researchers collected information on thumbsucking as well, they did not find it to have a negative effect on the emotional elements they measured. Thumbsucking may have been underreported; or it may be that thumbsucking is child-controlled rather than parent-controlled, and the participants may have self-limited the behavior in response to communication.

Boys will be boys
For reasons that are still unclear, in all three studies, girls’ demonstration of emotional development seemed to be unaffected by pacifier use. Niedenthal and colleagues have a few theories on why this may be the case. Perhaps parents who use pacifiers with their female babies “are inadvertently compensating for girls using the pacifiers, because they want their girls to be emotionally sophisticated … Because girls are not expected to be unemotional, they’re stimulated in other ways.” Girls may just receive more discussion of emotions than boy children do. By comparison, boys are expected to be unemotional, so parents who “plug them up with a pacifier, … don’t do anything to compensate and help them learn about emotions.”

Is pacifier use dangerous with boys?
If you use a pacifier with your baby boy, don’t be dismayed. Niedenthal and colleagues acknowledge that giving your baby a pacifier may be fine some of the time—particularly when it’s not going to interfere with communication and emotional expression. “We already know from this work,” Niedenthal explains, “that nighttime pacifier use doesn’t make a difference, presumably because that isn’t a time when babies are observing and mimicking our facial expressions anyway. It’s not learning time.”

This suggestion jibes well with the American Academy of Pediatrics’ (AAP) recommendation that parents consider offering their infants a pacifier at naptime and bedtime to reduce their risk of SIDS. The recommendation comes with some caveats, including:

• Pacifier use should be delayed until breastfeeding has been established (until at least 3–4 weeks of age).
• The pacifier should be offered when putting the infant down for sleep, but an infant who refuses the pacifier should not be forced to take it.
• The pacifier should not be reinserted during sleep if it falls out.
• The pacifier should not be attached to a string or other object (such as stuffed animals) that could interfere with breathing.

The latest study suggests an additional caveat:

• The pacifier should not be given when the infant has opportunities to develop skills of communication and emotion.

“Since a baby is not yet verbal,” Niedenthal explains, “and so much is regulated by facial expression—at least you want parents to be aware that using something like a pacifier limits their baby’s ability to understand and explore emotions. And boys appear to suffer from that limitation.”

In other words, parents of boys who choose to use a pacifier with their baby, especially during “learning times” may wish to give their infants additional opportunities to practice mimicry and emotional communication—binky-free.