How common is stuttering in children? What percentage of adults stutter? Do more men than women stutter?

Between 5% and 15% of children stutter at some point in childhood. As children get older, the prevalence drops to about 1% in junior high school and high school, and to about 0.1% for adults.

Of two- and three-year-olds, equal numbers of boys and girls stutter. The sex ratio becomes 3:1 by the first grade and 5:1 by the fifth grade, the same ratio as adults. 80% of adult stutterers are men.