It hasn’t been an easy week for Joe Biden. The former Vice President has been known for verbal blunders on the debate stage, even calling himself a “gaffe machine” at one point, but he has always maintained that his slip ups are innocuous mistakes that shouldn’t carry weight.

"Look, I think it's fair to go after a political figure for anything," Biden said in an interview on The Late Show with Stephen Colbert earlier this September. "OK. I mean, we stand up and that comes with the territory. But here's the deal, any gaffe that I have made, and I've made gaffes like every politician I know has, have been not about a substantive issue."

Biden’s performance on Wednesday night’s debate was no exception, starting out with a misstatement that the Democratic presidential candidate was endorsed by “the only African American woman ever elected to the Senate,” while sharing a stage with none other than Senator Kamala Harris, the second African American woman to be elected to the Senate. While punishment was swift and Biden quickly corrected himself, he then turned his attention to the issue of sexual violence against women — saying that Americans need to end the culture of male violence and “keep punching it and punching it and punching it.”

Since Biden’s gaffes are a recurring issue, the question is why they continue to happen, and should voters be worried by their implications, especially considering that Biden claims to be the most qualified person in the country to be president.

A lifelong battle

It’s been reported by the media before, even framed as a question of why more people aren’t talking about, but a recent feature by The Atlantic puts it into clear view — Joe Biden has a stutter.

“We’ve been tiptoeing toward it for 45 minutes, and so far, every time he seems close, he backs away, or leads us in a new direction. There are competing theories in the press, but Joe Biden has kept mum on the subject. I want to hear him explain it,” starts John Hendrickson for The Atlantic. “I ask him to walk me through the night he appeared to lose control of his words onstage.”

Biden’s stutter, which he has said has affected him since childhood, is almost always undetectable for those who aren’t looking for it. But that doesn’t mean that it isn’t constantly making its presence known to the speaker himself, making it difficult to form certain sounds — a predicament only exacerbated further by nerves.

For people with stutters, it's not just difficulty with speaking that can be a major frustration in their lives, it’s the negative cultural perception they must deal with as well.

Perhaps you’ve watched the movie The King’s Speech starring Colin Firth as King George VI, whose impromptu ascension to the throne of the British Empire was made even more stressful by his difficulty giving a speech due to a speech impediment. The movie accurately portrays the humiliation he endured while trying to overcome his stammer and the unfair labels that are placed on people with stutters, who may be seen as anxious or incompetent by those unfamiliar with its effects.

What the movie gets wrong is the myth that the King’s stuttering is a result of childhood trauma, which has never been proven to be linked to the formation of a speech impediment. Stuttering is a neurological disease that affects 70 million people around the globe and 3 million in the U.S. alone — causing a person to repeat or prolong sounds, syllables, or words and disrupting the normal flow of speech. The cause of stuttering long baffled scientists until they discovered gene alterations that they now believe play a key role in the formation of the disorder. While new studies on medications such as Ecopipam show promising results for adults who stutter, roughly 25 percent of affected children currently experience symptoms of the disorder for life.

“When King George VI, when he stood up in 1939, everyone knew he stuttered, and they knew what courage it took for him to stand up at that stadium and try to speak — and it gave them courage … I could feel that. It was that sinking feeling, like — oh my God, I remember how you felt. You feel like, I don’t know … almost like you’re being sucked into a black hole,” Biden told Hendrickson.

What Biden’s speech impediment means for his race to the Oval Office

Some have been quick to question Biden’s mental fitness, hinting at a possible age-related cognitive decline (he just turned 77 years old), but it’s important to consider that many of those missteps could have been caused by his lifelong struggle with a speech impediment.

NYU speech pathologist Eric S. Jackson explains, “Stuttering can be thought of as a neurobiological ‘glitch’ — broadly speaking, the neural processes that are involved in speech, at times, don’t function like those in non-stuttering speakers. The glitches manifest themselves as intermittent and somewhat unpredictable interruptions in speech, typically repetitions of syllables or audible/inaudible prolongations of sounds. The speaker knows precisely what he or she wants to say, but in that moment, their body temporarily prevents them from producing speech.”

Stuttering is recognized as a disability under the Americans with Disabilities Act. While Biden’s verbal missteps don’t cast him any favors on the debate floor, just him being a person with a speech impediment running for the highest office in the country is a powerful reminder for young people who may feel limited by their disabilities.

“If I could share one piece of advice with all of those struggling with a stutter, it would be this: When you commit yourself to a goal and when you persevere in the face of struggle, you will discover new strengths and skills to help you overcome not only this challenge, but future life challenges as well. I promise you — you have nothing to be ashamed of, and you have every reason to be proud,” Biden penned in a 2015 letter to the Stuttering Foundation of America.