What is a core behavior characteristic of normal stuttering?

A core behavior characteristic of normal stuttering is indeed one-unit repetitions. This type of disfluency is commonly observed in individuals who stutter, particularly in children who are developing their language skills. One-unit repetitions involve repeating a syllable, sound, or word, such as saying "bu-bu-butter." This form of repetition is typically brief and often occurs in a rhythmic pattern, making it a characteristic feature of normal stuttering behavior.

In contrast, the other options describe disfluencies that may not be as characteristic of typical stuttering or reflect a different pattern of speech disfluency. While more than 10 disfluencies per 100 words can occur in various speech contexts, this measure alone does not specifically indicate stuttering. Prolongations, though also a feature of stuttering, are not necessarily the most common form seen in typical cases of stuttering, as they can vary widely from person to person. Frequent use of interjections can arise in fluent speech as well and is not exclusive to individuals who stutter.

Understanding these nuances helps differentiate typical stuttering behaviors and informs appropriate intervention and support strategies.