Infants

Monkey baby mama talk

LiveScience brings together two fascinating studies on motherese--the swooping, exagerated way that mothers speak to their babies. In the first study, scientists played different examples of English baby-talk to a group of non-literate, hunter-horticulturalists in Ecuador who speak Shuar. The Shuar-speakers could tell what the English mothers intended over 70% of the time. But baby-talk isn't just human. It turns out that rhesus monkey mothers also speak to their babies with exagerated, musical pitch.


How much does your baby know?

Young babies don't do a lot, but every year we discover there is a lot more going on inside than you can tell. The latest news is that four-month-olds already have an idea about the shape of a word. EEG measurement showed that infants this young recognize patterns of word stress that are specific to language, and they are better at recognizing words from their own language. Previously, only 6 to 12-month-olds had been shown to have knowledge about their language. Current Biology.


When language explodes

Children typically acquire a few words very slowly and then around 2 years of age undergo a 'word explosion.' A cognitive scientist at the University of Iowa has built a mathematical model which suggests that this amazing phenomenon is not genetically controlled, as has long been thought. Instead children experience a burst in learning because language consists mostly of words that are medium-hard to learn. There are many fewer easy and hard words. The word spurt is just a byproduct of the learning process and the nature of language. The pattern of slow growth up until a crucial threshold is, apparently, true for many domains in which children learn, such as music, art, and athletics. Why Files, New Scientist, Bob McMurray.


Vowel geography

Young infants can distinguish subtle contrasts that exist in speech sounds of all languages of all the world. English babies, for example, hear the difference between Zulu clicks, something that untrained English adults are hopeless at. This ability is lost as children zoom in on the distinctions made in their native language. Researchers at Stanford have built a model that suggests children learn vowel contrasts in their own language because of general, innate biases. These inborn tendencies allow young language-learners to work out how many different vowels exist in their language and where they lie with respect to each other.  Moreover, the swooping, exaggerated way that parents speak to their children makes it easier for them learn the differences between vowels in their native language. PNAS.


Native speakers prefer... native speech

The tendency to favor your own social group over others emerges before you've learned anything about current disputes or historical conflict, before you've even learned how to talk. Children show strong early preferences for people speaking their native language, say researchers at Harvard and the Centre National de la Recherche Scientifique. They suggest this linguistic favoritism may underlie conflict between social groups.
    In a series of experiments, the team showed that even before infants produce, or they say, comprehend speech, they prefer to look at speakers of their native language over speakers of a different language, and they prefer to take toys from speakers of their native language. Additionally when five-year-old native English speakers were shown photographs of two children and played a recording of either an English or a French speaker, they said they'd choose the child who spoke their native language as a friend. A similar experiment showed that children prefer other children who have their native accent over children who speak their native language but with a foreign accent.
    These findings are not exactly surprising. Would anyone expect anything else? Still, the researchers hope that understanding how the foundations of social conflict develop may help contribute to their solutions. PNAS. Press links to come.


Seeing voices

In the last five years a lot of evidence has emerged about the abilities of babies, and indeed the abilities of monkeys, to make subtle judgments about language. For example, human babies and tamarin monkeys can tell one language from another based upon its rhythm. I'm just catching up on the last month's news that babies are also adept at distinguishing foreign languages, like English and French, just by looking at the way a speaker's face moves. This miraculous ability exists between four- and six-months of age and it fades away between six- and eight-months, unless the baby lives in a bilingual household Science News, Science.


How to say goodbye

Twenty-seven thousand years ago, a human parent or parents buried their ten-month-old twins. They decorated their babies with red ochre and jewellery, and sheltered them under the shoulder blade of a mammoth. The huge animal scapula protected the infants, and their well-preserved remains were uncovered in Austria in 2005. (Another child was buried nearby). I recently came across this piece about the sad pair in Scientific American, written in 2006. Live Science has good pictures. The find was originally reported in Nature.


What goes around...

The latest research on altruism in apes may not be as surprising as the selfless rats in the previous post--because, of course, chimpanzees and humans are much more closely related--but it's all good, solid evidence that sharing can be as sensible an evolutionary move as selfishness, even if these chimpanzees reported in PLoS do it with non-family members. The same researchers show that both human infants and chimpanzee young will help without expecting a reward. BBC.