Five-month-old babies prefer their own languages and shun foreign accents

ByEd Yong
June 14, 2009
5 min read

Discriminating against people who do not speak your language is a big problem. A new study suggests that the preferences that lead to these problems are hard-wired at a very young age. Even five-month-old infants, who can’t speak themselves, have preferences for native speakers and native accents.

The human talent for language is one of our crowning evolutionary achievements, allowing us to easily and accurately communicate with our fellows. But as the Biblical story of the Tower of Babel relates, linguistic differences can serve to drive us apart and act as massive barriers between different social groups.

These barriers can give rise to linguistic discrimination, a far more insidious problem that it seems at first. Language-based prejudices have led to horrific acts of human abuse, and even civil wars. Genocide often finds itself paired with linguicide, since a race can be killed off more thoroughly if their language follows them.

Even today, people in a linguistic minority can find themselves denied access to healthcare, or at a disadvantage when looking for jobs. The issue cuts to the heart of several ongoing debates, from the role of second languages in education to whether immigrants must become fluent in the tongue of their host country.

It should therefore be unsurprising to learn that we have strong preferences for our own language and for those who speak it. But Katherine Kinzler and colleagues from Harvard University, have found that we develop these preferences from an incredibly young age, before we can speak ourselves, and well before we can even hope to understand the social issues at stake.

Kinzler tested 24 infants, aged 5 to 6 months, from households that only spoke English, to see if they had any linguistic preferences. Each toddler watched videos of two women, one speaking English and the other, Spanish. The women were all bilinguals and swapped the language they used in different trials to make sure that the babies weren’t showing preferences for physical traits like skin colour.

The babies were then shown the two women side by side, but no longer speaking. They strongly expressed their preference for the English speakers by gazing at their screen for a longer time (measuring gaze time like this is a standard test used by child psychologists).

Once developed in early infancy, these preferences stick around into childhood, and most probably well beyond that. In very similar experiments, Kinzler found that older infants (10 months or so) prefer to accept toys from a woman who spoke their native language.

The babies, from either Boston or Paris, were shown alternating films of an English or French-speaking woman, who spoke for a while and then silently offered the child a toy. Two real toys then appeared on the table in front of the infant, and they were twice as likely to pick the one in front of the native speaker.

So even though the offering of the toy involved no spoken words, the infants still gravitated towards the woman who had spoken earlier in their familiar tongue.

Infants can even pick up on subtle differences in dialect. Even when two speakers are talking in the same language, 5-month old infants will prefer someone who speaks with a native accent to someone who speaks with a foreign twang. Older children (5 years or so) will similarly prefer to befriend another child who speaks with the same accent.

At that age, children will have barely any understanding of the social circumstances that leads to different groups of people speaking the same language in different ways. And it’s unlikely that their parents had much influences, since even the 5-month-old toddlers had these preferences.

These early preferences can act as the foundations for more destructive behaviours and conflicts later on in life. But we must be very careful – an instinctive basis for a behaviour does not in any way justify it.

Instead, by telling us about the basis of linguistic prejudices, these results suggest that we must work even harder to overcome them. If they are hard-wired from an early age, then education from an early age seems like a sensible first step.

Perhaps, exposure to multiple languages early in life can soften these preferences, and it would be fascinating to see if the same results hold for babies from bilingual households.

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