What to Know About Stuttering

For a couple of minutes on Thursday, the sprawling, virtual Democratic National Convention seemed to hold its collective breath as 13-year-old Brayden Harrington of Concord, N.H., addressed the nation from his bedroom, occasionally stumbling on his words. “I’m a regular kid,” he said into a home camera, and a recent meeting with the candidate “made me feel confident about something that has bothered me my whole life.”

Joe Biden and Mr. Harrington have had to manage stuttering, and the sight of the teenager openly balking on several words, including “stutter,” was a striking reminder of how the speech disorder can play havoc with sociability, relationships, even identity. Movies like “The King’s Speech,” and books like Philip Roth’s “American Pastoral,” explore how consequential managing the disorder can be, just as Mr. Biden’s own story does.

How many people stutter?

The basic numbers are known: About one in 10 children will exhibit some evidence of a stutter — it usually starts between ages 2 and 7 — and 90 percent of them will grow out of it before adulthood. Around 1 percent of the population carries the speech problem for much of their lives. For reasons not understood, boys are twice as likely to stutter, and nearly four times as likely to continue doing so into adulthood. And it is often anxiety that triggers bursts of verbal stumbling — which, in turn, create a flood of self-conscious stress.

When Mr. Harrington got stuck for a couple of seconds on the “s” in “stutter,” he turned his head and his eyes fluttered — an embodiment of physical and mental effort — before saying, “It is really amazing that someone like me could get advice from” a presidential candidate.