The mean length of utterance increases as children develop. This increase most directly reflects growth in which aspect?

The mean length of utterance increases as children develop. This increase most directly reflects growth in which aspect?

• A. Increase in daily spoken word count only.
• B. Increase in the number of conversational partners.
• C. Growth in syntactic complexity and utterance structure.
• D. Improvement in memory for lists of words.

Answer: (C)

The main idea here is that mean length of utterance rises as children’s language becomes more grammatically and structurally complex. MLU is not just about saying more words; it measures the average number of morphemes per utterance, so it captures the addition of syntax, inflection, and combining words into longer, more varied sentences. As kids develop, they move from single words to phrases and sentences with subjects, verbs, objects, and function morphemes (like -ing, -ed, -s). That growth in sentence structure and complexity is what drives the increase in MLU. So the best answer points to growth in syntactic complexity and utterance structure. The other options miss the key idea: simply speaking more words overall doesn’t necessarily reflect more complex sentence structure; having more conversational partners relates to exposure but not the inherent structural development measured by MLU; and memory for lists doesn’t directly reflect the grammatical and connective growth shown in longer, more complex utterances.

The main idea here is that mean length of utterance rises as children’s language becomes more grammatically and structurally complex. MLU is not just about saying more words; it measures the average number of morphemes per utterance, so it captures the addition of syntax, inflection, and combining words into longer, more varied sentences. As kids develop, they move from single words to phrases and sentences with subjects, verbs, objects, and function morphemes (like -ing, -ed, -s). That growth in sentence structure and complexity is what drives the increase in MLU.

So the best answer points to growth in syntactic complexity and utterance structure. The other options miss the key idea: simply speaking more words overall doesn’t necessarily reflect more complex sentence structure; having more conversational partners relates to exposure but not the inherent structural development measured by MLU; and memory for lists doesn’t directly reflect the grammatical and connective growth shown in longer, more complex utterances.