Emotions Underlie Babies' Blather: Communication in Early Months Tied to Language Learning
Bower, Bruce, Science News
Babies take a crucial step toward learning to speak before they can say a word or even babble. By 3 months, infants flexibly use three types of sounds--squeals, growls and vowel-like utterances--to express a range of emotions, from positive to neutral to negative, researchers say.
Attaching sounds freely to different emotions is a building block of spoken language, say psycholinguist D. Kimbrough Oller of the University of Memphis in Tennessee and his colleagues. Any word or phrase can signal any mental state, depending on context and pronunciation. Infants' flexible manipulation of sounds to signal how they feel lays the groundwork for word learning, the scientists conclude April 2 in the Proceedings of the National Academy of Sciences.
Language evolution took off once this ability emerged in human babies, Oller proposes. Ape and monkey researchers have mainly studied vocalizations that have one meaning, such as distress calls.
Oller's group videotaped infants playing and interacting with their parents in a lab room equipped with toys and furniture. Acoustic analyses identified nearly 7,000 utterances made by infants up to 1 year of age that qualified as laughs, cries, squeals, growls or vowel-like sounds. …