Flexible learning system allows humans to keep up with linguistic change, researchers find

November 6, 2012 by Susan Kelley

(Phys.org)—Unlike other species, humans speak to each other in remarkably diverse ways. Some of our 6,000 to 8,000 languages use clicks (!Kung). Others don't differentiate between nouns and verbs (Straits Salish). Still others pack a whole sentence into a single word (Cayuga). In comparison, the communication systems of other animals show precious little variation within species; vervet monkeys use the same communicative signals across their geographical range, just as honeybees, bacteria and every other species each have one way of communicating.

So how have humans developed so many when other species have not?

A Cornell researcher and his colleagues now say they know why. The diversity of is made possible because we have evolved a flexible learning system to keep up with the rapid linguistic change associated with human migrations, according to a new study published Oct. 30 in the journal .

"Only biological adaptations for flexible learning combined with cultural evolution can explain the astonishing while still allowing each child to learn any human language," said co-author Morten Christiansen, professor of psychology and co-director of the Cornell Cognitive Science Program.

To reach their conclusions, the researchers created a computer model to explore the effects of on . As humans spread across the globe, the languages of geographically separated groups quickly ended up becoming different from one another through processes of cultural evolution. The model indicates that humans have evolved a flexible learning system to follow such rapid linguistic change.

"Importantly, the model assigns a crucial role to linguistic change, which has been extraordinarily rapid during historical times. For example, the entire Indo-European language group diverged from a common source in less than 10,000 years—the blink of an eye in evolutionary terms," Christiansen said.

The researchers speculate that the cultural evolution of language may have "recruited" preexisting brain systems to facilitate its use, just as reading relies on neural substrates that predate the invention of writing.

The findings have important implications for understanding the origin of language and human cognition: Humans have evolved a flexible learning system for keeping up with the rapid cultural evolution of language, instead of a special-purpose linguistic system analogous to the visual system. Likewise, variation in social and religious practices may similarly be seen as products of such flexible learning, rather than evolved wiring for moral behavior.

Explore further: Language driven by culture, not biology

More information: Christiansen, M. et al. The Biological Origins of Linguistic Diversity. PLoS ONE, Oct. 30, 2012.

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1 / 5 (1) Nov 06, 2012
Hearing and Speaking are biological adaptations to planets with atmospheres.
Atmospheres provide mechanical waves (sound).
Sound provides diversity.
The limits to the diversity of sound are the limits to the resolutions of the senses evolved to manipulate mechanical waves.

So, I leave you with the thought exercise of the day:

As far as, and in the case, where humans are concerned, evolution led to sound production (speech) and sound processing (hearing.)

What prevented humans from utilizing light production (flashlights are cheating) along side light processing (sight?)
1 / 5 (1) Nov 06, 2012
Congratulations go to the researchers and research. Kudos.
not rated yet Nov 06, 2012
This sounds a little like putting the cart before the horse. Wouldn't the evolution of the ability to handle language in software have had to evolved BEFORE we left Africa? It seems to me that whatever happened to differentiate humans created both our language capabilities and our intelligence levels at the "same time". This in turn helped us to migrate out of Africa and adapt to many different environments.
3 / 5 (2) Nov 06, 2012
Wouldn't the evolution of the ability to handle language in software have had to evolved BEFORE we left Africa? - Dz

The article supports your statement/assertion above with:

The researchers speculate that the cultural evolution of language may have "recruited" preexisting brain systems to facilitate its use, just as reading relies on neural substrates that predate the invention of writing.

'Language capabilities' must preexist.
Sensory 'input' stimulates 'intelligence'.

The answer to your question is yes. The article agrees.
The 'timing' and 'maturity' of language capabilities and intelligence is irrelevant to migration as long as any those aspects take place before migration.

Although migration is possible without language capabilities and intelligence (viruses) the possibility of that becomes unlikelier the higher you climb the tree of life forms.

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