When a young child is learning to write letters or a baby is attempting to imitate their parents, the protruded tongue is frequently our proof of the child’s intense focus. However, it’s not only children; during really challenging jobs, even adults will stick out or press their tongues to the roofs of their mouths. So why does intense thought make us tense up, clamp down, and even stick out our tongues?
When you’re focused, it may appear like you’re putting out your tongue, but it’s actually a result of what you’re doing. Gillian Forrester is a professor of comparative cognition and the acting head of Birkbeck University of London’s School of Science. “What we’ve discovered is that when people are doing anything delicate that involves fine motor activation of their hands, they [put out their tongue],”
The motor overflow hypothesis is one explanation for why this occurs. According to a 2019 study published in Frontiers in Psychology, neuroimaging shows that the area of the brain responsible for language (placed in the inferior frontal gyrus) is substantially overlapping with neural networks responsible for dexterity and tool usage (opens in new tab). According to motor overflow theory, the dexterity region’s neurons are so hyperactive that they spill over into nearby brain tissue (which happens to direct the mouth). So when you’re really concentrating on a fine-motor job, the influence “spills over” into the language region, leading you to utilize your lips and tongue.
According to Forrester, this theory probably has a role in what’s happening. Forrester told Live Science that the tongue and hands are the “only fine articulators on our body and are controlled by overlapping portions of our brain” in the left hemisphere. The above-mentioned 2019 study(opens in new tab) discovered that motor competence predicts language creation, particularly when employing sophisticated instruments. The authors draw the conclusion that this indicates that language and tool usage (fine motor abilities) share a cognitive process.
However, the science around the tongue-concentration habit is far from conclusive. According to Forrester, there is probably more to the narrative and it could even include evolution.