Anyone can slip up on a word every now and then. It's very common in children but usually they grow out of it. I have met many people who told me that they "grew out of it when they were young" this is simply not the case for me and for a few million other people on earth. In fact, Of the 1% of the population, only a quarter of that is girls. A new study suggest that the physical structure of the brains pathways between the left and right hemisphere are far more active in females who stutter than males into adulthood.