Goethe-Universität Frankfurt am Main Oct 9 2025 While stuttering was believed to have purely psychological causes up until about 30 years ago, scientists today attribute it to a variety of factors capable of contributing to its development. For instance, several genes have been identified that increase the risk of stuttering, and anatomically, the brains of individuals with speech flow disorders show differences in neural connections and brain activity compared to those who speak fluently. The