1. Simulated Evolution of Language By: Jared Shane I400: Artificial Life as an approach to Artificial Intelligence January 29, 2007

2. Introduction What evolutionary forces propelled the development of language? Are the language abilities of humans the result of a language-specific portion of the brain or do they result from a general application of our cognitive abilities?

3. Introduction (cont.) - These questions are the oldest and most difficult to answer. Only within the last century that the sciences of evolutionary biology, computation, psychology, and cognitive sciences have been able to provide direction and focus in search for answers

4. Theories of Language Evolution What is the heart of human uniqueness? –Characteristics that separate humans from animals. –One of the most important factors separating humans from animals is the use of language –Humans have exceptional language skills relative to animals, as well as more powerful intellectual skills

5. The Birth of Language The controversy and the approach started by Noam Chomsky in the middle of the 20 th century –He published his ideas regarding the biological basis of language Since then, most history has been a response to him Two views taken Nativist vs. Non-nativist

6. The Nativist View The pure nativist believes that language ability is deeply rooted from in the biology of the brain. –They claim our ability to use grammar and syntax is an instinct, or dependent on specific modules of the brain, or both.

7. The Nativist View (cont.) Reasons for believing the nativist view: –Genetic/biological data –Research in child acquisition Nativists claim that there are many mistakes that children do not make They claim children are able to learn language fluently if they are exposed to it before age 6

8. The Non-Nativisit View Children learn through the properties of their parents speech Words and phrases used most commonly by parents will be first words, phrases, and even grammatically structures learned by children Much evidence supporting the non-nativist view is evidence against the nativist view

9. The Non-Nativisit View (cont.) Evidence indicates children pay more attention to some words than others Only after children generalize verbs to a variety of contexts and forms do they begin to acquire verbs The final argument for the non-nativist is the best theory is usually the one that incorporates the fewest unnecessary assumptions

10. The Evolution of Language Any scientist hoping to explain language evolution needs to explain two things: –The first usage of words as symbols “Evolution of Communication” –The first usage of what we might call grammar “Evolution of Syntax” Three dominant theories of language evolution –Bickerton: Incorporating the fossil record –Pinker and Bloom: On Natural Selection –Deacon: The Natural Selection of Language Itself

11. Bickerton: Incorporating the fossil record 1990, Derek Bickerton authored a theory based on the notion of Primary Representation System (PRS) –The way in which humans represent the world forms the basis for the structure of human language, which evolved in stages He proposed that the PRS of humans is fundamentally binary and hierarchical –The concept in our minds that seem to correspond to notions in the world are defined horizontally as well as vertically

12. Bickerton (cont.) Another reason for believing full language did not exist until recent: –There is little evidence in the fossil record prior to the beginning of the Upper Paleolithic (1000,000- 40,000 years ago) One drawback to Bickerton’s theory: –The problem with an explanation relying on a sudden genetic mutation is that on many levels it is no explanation at all. –It takes an unsolved problem in linguistics and answers it by moving it to an unsolved problem in biology

13. Pinker and Bloom: On Natural Selection In 1990, Pinker and Bloom argued that human language capacities must be attributed to biological natural selection based on two criteria: –Complex design –Complexity is a characteristic of all human languages –The absence of alternative processes capable of explaining such complexity –Demonstrates that there are no processes other than biological natural selection that can explain the complexity of natural languages

14. Pinker and Bloom (cont.) Evidence seems to argue that the language must be the product of biological natural selection, but there are drawbacks. –They do not suggest a plausible link between their ideas and what we currently know about human evolution –They never put forth a believable explanation of how an additional mutation in the form of one more grammar rule would give an individual selection advantage –These arguments are vulnerable in some areas to counter-arguments based primarily on the notion of that general intelligence may be the key to our language understanding

15. Deacon: The Natural Selection of Language Itself One of the arguments to the viewpoint that language is the product of biologically-based natural selection is the idea that rather than the brain adapting over time, language itself adapted This view is not vulnerable to many of the basic problems with other views –It's difficult to account for the relatively rapid rise of language ability reflected in the fossil record with an account of biologically based evolution Another powerful and attractive aspect of Deacon’s theory is its simplicity –It acknowledges that there can be linguistic universals

16. Questions and/or Comments?? Thank You!

17. Reference Information Amy Perfors. “”Journal of Artificial Societies and Social Simulation.” Simulated Evolution of Language: a Review of the Field. 31 March 2002. 23 January 2007. http://jasss.soc.surrey.ac.uk/5/2/4.html http://jasss.soc.surrey.ac.uk/5/2/4.html