The preference is so entrenched that by age 5 children prefer playmates who not only speak the same language but do so with the same accent.
A key implication of the findings – reported in the US publication Proceedings of the National Academy of Science – is that children exposed to different languages grow into more tolerant adults than those familiar with only one language.
Cognitive psychologist Elizabeth Spelke of Harvard University in Cambridge, Massachusetts, conducted a series of experiments with Harvard doctoral student Katherine Kinzler and Emmanuel Dupoux of the National Centre for Scientific Research (CNRS) in Paris.
They judged the preferences of three groups of children. Infants aged 5 to 6 months looked at native speakers longer than non-native speakers. Babies aged 10 months selected toys most often from native speakers, and most 5 year olds chose native speaking playmates over children with an accent.
According to Professor Spelke, the most surprising result came from the group’s experiment with 5 year olds. “The findings suggest that (the preference) has nothing to do with information, the semantics of language, but rather with group identity,” she said.
The researchers suggested that such early preferences may develop into criteria for making judgments about strangers, in the same way that race and gender can colour people’s perception.