Cross-fostering experiments suggest that the main reason primates do not produce human-like variety in their vocalizations is because apes
A) lack the motivation to speak.
B) are not raised in the same language-evoking way human infants are.
C) lack the physical apparatus and control over it to produce human-like speech.
D) cannot breathe and swallow simultaneously.

Question

Quizplus · Accepted Answer

Cross-fostering experiments have shown that primates raised in a human-like language environment still do not produce human-like speech. This suggests that the physical apparatus and control over it required for human-like speech production is lacking in primates.

Cross-Fostering Experiments Suggest That the Main Reason Primates Do Not