Wednesday, November 11, 2009

Bawling like a baby....but which baby?

A study published last week in Current Biology reports that newborns already speak their mother's language (Current Biology 19, 1–4, December 15, 2009, Newborns’ Cry Melody Is Shaped by Their Native Language, Birgit Mampe et al.). Or rather, the tonality of their cry tends to mimic the intonation of their native language (you can listen to the differences here). The researchers analyzed the cries of 30 French and 30 German newborns and found that the cries of the French babies tended to rise, while those of the German babies fell, both in line with the intonation patterns of the language spoken by the infants' mothers. This was a repeatable observation, according to the authors, who attributed it to what they heard around them in their last trimester of gestation (amazing! They didn't say there was a gene for the trait!).

This isn't really a surprise, as the same sorts of results were found by psychologist Gilbert Gottlieb when, in the 1960's and 70's, he experimented with embryonic ducks to determine whether responding to their mother's vocalizations was learned or innate. He devocalized embryos so they couldn't make their own sounds in the egg, which they do naturally, and raised the eggs in isolation so they weren't hearing their own or their mother's vocalizations.  He found that they didn't respond readily to their mother at hatching, unlike chicks that develop normally.

In fact, Gottlieb was a central figure in the growth of developmental systems theory, the idea that genetics is generally considered to be far more integral to development than it actually is, and that evolutionary theory should be less centered around genes.  Evidence for the effects of the environment on gestational development in general, and on language learning specifically, is nothing new, and the fact that the current story has made such a splash suggests another case of ignoring what's already known (a state of affairs that we discussed here). 

We tend these days to attribute everything to genes and hard-wiring, because that fits our current culture's deterministic predisposition. There is a tension between human exceptionalizing--making us different from other species--and the juicy, almost prurient need many geneticists seem to feel to pry into our genomes and discover what really makes us what we are.  In a way, that's different from giving us free will, which many in our society would like to do.

Of course, we know very well that the uterine environment can affect us in many ways. Even late-onset disease risks reflect pre-natal effects. But we have tended to attribute behavioral traits to either post-natal learning--or to genes. The baby crying study reminds us of something we already know--gestational learning can make behaviors look like instinct.


Jennifer said...

so what does a Japanese baby cry sound like?

Ken Weiss said...

They're stoic: they don't cry