3-month-old Sheila and her 2-year old sister Betty have only been exposed to English. They are habituated to a non-English phoneme (/ka/). Sarah turns her head when a new, non-English phoneme is presented (/kka/). Betty, however, does not turn her head when this new phoneme is presented. Why is this so?
A)
Betty is subject to universal phoneme sensitivity and is, therefore, unable to distinguish between the two phonemes.
B)
Betty is subject to an overextension and is, therefore, mistaking the two phonemes as being the same.
C)
Betty is subject to an underextension and is, therefore, mistaking the two phonemes as being the same.
D)
Betty is subject perceptual narrowing and is, therefore, unable to distinguish between the two phonemes.
Answer: D