So much happens in the mind of a child who won’t speak. In Gunter Grass’ classic German novel The Tin Drum, three-year-old Oskar — self-declared as “sentient at birth” — decides to forever stop speaking, choosing instead to bang his drum, issuing on occasion a shrill whistle capable of breaking glass. Outside the realm of magical realism, however, kids that age might hesitate to speak for simple social fear, a new study suggests.

Investigators from the University of Connecticut and the University of Colorado, Boulder conducted a longitudinal study of more than 800 toddlers. They found that socially inhibited children are more reticent in conversation, as you might expect. However, the study findings contradict previous research suggesting shy kids experience trouble with language development.

"Our findings suggest that inhibited behaviors like shyness don't hamper language acquisition overall but instead relate specifically to how toddlers express themselves through words,” investigator Soo H. Rhee, an associate professor of psychology at the University of Colorado, said in a statement. Interestingly, they found girls to be more reticent than boys overall, though shyness related to language development to a similar degree in both sexes.

In the study, investigators analyzed data from 816 children in Colorado who were mostly white but of a variety of socioeconomic backgrounds, representative of the Boulder population. At age intervals of 14, 20, and 24 months, Rhee and her colleague, graduate student Ashley K. Smith Watts, collected follow-up information from parents and by laboratory and home visits. In assessing a toddler’s spoken language ability, the researchers asked kids to answer questions with a verbal response, and also to imitate sounds and words. They then tested language comprehension by directing children to follow instructions in a simple task, such as retrieving a ball and a cup.

In considering possible therapeutic interventions for shy kids, investigator Smith Watts suggested playdates with like-minded peers, for one. "They may benefit from interventions that target confidence, social competence, and autonomy to support the development of expressive language,” she said in the statement.

Source: Rhee, Soo H., Smith Watts, Ashley K. Child Development. 2014