After ninety hours, children in the intervention group made 73 English utterances per hour, five times more than those in the control group taught English by Spanish nursery teachers. The intervention group also showed improvement in both L1 and cognitive learning skills. Spanish education officials, however, have questioned the validity of the control group, pointing out that English is not usually taught at this age. The data on this study has yet to be published.
The study was led by Dr Patricia Kuhl, professor of early childhood learning at the University of Washington. Kuhl’s work on early childhood language acquisition challenges assumptions in second language acquisition theory. Her hypothesis is that babies use ‘phonetic learning’ – the ability to discriminate all 800 sounds used in the world’s languages – to acquire language, with their acquisition mediated by social interaction.
Most researchers agree this ‘sound window’ begins to close when babies reach the age of around twelve months, but Kuhl’s work – both in the Madrid nurseries and in a mirror study in US pre-schools – shows that ‘hyper-stimulating’ social interaction with native speakers using ‘motherese’, the phonetically exaggerated speech used by parents, can enable children as old as three to acquire a second language through phonetic learning. She warns, however, that this ability declines and may be absent in most monolinguals aged six and up.
In an El Mundo interview the professor makes no mention of native speakers, highlighting instead the use of motherese. Asked about the results achieved by Spanish nursery workers in the control groups, where children used 80 per cent less English, she emphasised the importance of stimulating children though play and interaction. Other Spanish press reports, however, emphasised the use of native speakers, and Kuhl in a 2016 paper states, ‘Infants learn best through frequent high-quality social interactions with native speakers.’
Spanish local education officials point out that the aim of Spain’s bilingual system is to produce good L2 speakers rather than true bilinguals. Their concerns about the use of native speakers, however, may be misplaced. Kuhl’s work suggest that the use of native speakers won’t increase the phonemic competence of learners over the age of six.