Do infants show a preference for looking at faces talking in their native language?

Infants have been known to be able to distinguish between two languages using just the visual cues to speech – the movement of the mouth and rest of the face. In this study, we ask whether infants show a preference for their native language when they just have access to the visual cues to speech.  4- and 8-month-old infants were presented with side-by-side videos of a bilingual speaker producing English and Spanish and we measured how long they looked to each video.  Infants learning only-English and bilingual English-Spanish-learning infants were tested.  Results show that English-learning infants looked longer and more often to the English stimuli, demonstrating a native language preference.  Bilingual infants, with exposure to both English and Spanish, looked equally often at both languages.

English-learning 4- and 8-month-olds were also tested to see if they still showed a preference for their native language when they could only hear speech, but not see anyone talking.  Interim results suggest that 4-month-olds showed no preference, but 8-month-olds do, confirming previous research.

English-learning 4-month-olds were also tested on their preference between Dutch and Spanish.  Dutch is a language that is closely related to English and shares many features.  For example, they have similar speech rhythms.  Spanish, on the other hand, is considered to be rhythmically distinct from English/Dutch.  If infants preferred English over Spanish – that is, if infants were able to identify English as their native language and Spanish as a non-native language – using rhythm properties, then they should treat Dutch like their native language and prefer it over Spanish, as well.  On the other hand, if they identify English by language-specific movements of the mouth and face, they should show no preference between Spanish and Dutch, since both will be non-native.  According to interim results, when presented with side-by-side videos of a bilingual speaker producing Dutch and Spanish, 4-month-old English-learning infants show a preference for Dutch over Spanish.