Fluency. When we think of stuttering, we might first think of speech therapy, of pauses and repetitions, and of the courage it takes to speak when words get stuck. But what if we could step back and see its genetic architecture laid out across the globe? A recent study looked at the genetics of stuttering at an unprecedented scale: over 1.1 million individuals, including almost 100,000 people who self-reported a history of stuttering. Stuttering shows a significant overlap with other neurodevelopmental disorders and enrichment of genes expressed in the brain. Here is a brief summary of one of the most important studies in stuttering research in the last few decades.