1. Psy1302 Psychology of Language Lecture 22 Evolution of Language

2. Exercise: Creating a Communicative System

3. Unique Things about Human Language How is Language Special

4. Unique Things about Human Language Big, discrete vocabulary Big, discrete vocabulary –10,000-100,000 “words”… or more Recursive compositionality Recursive compositionality –making bigger messages by combining smaller ones, –more complex meanings by combining simpler ones Action to “change others’ minds” Action to “change others’ minds” –we know others may have different knowledge and beliefs –we communicate to inform, persuade, deceive, etc. How is Language Special

5. A puzzle: why? Quantitatively and qualitatively unique Quantitatively and qualitatively unique –like elephants’ trunks No similar evolutionary trends in other species No similar evolutionary trends in other species –other species don’t “want” to pick up peanuts with their noses all mammals have noses, some use them as manipulators all mammals have noses, some use them as manipulators no general trend to develop anything like trunks no general trend to develop anything like trunks –other species don’t “want” to exchange very complex messages (nearly) all mammals make noises, some use them to communicate (nearly) all mammals make noises, some use them to communicate no general trend to develop anything like human speech no general trend to develop anything like human speech How is Language Special Slide from Liberman

6. Why do humans have language? Any thoughts??? Any thoughts??? –Because we’re smarter than other animals? –Because we have a bigger brain? –Because our mouths have a special shape? –Because somebody took the time to teach us? –…or because that’s just something that humans do?

7. Chomsky If an animal had a capacity as biologically advantageous as language but somehow hadn’t used it until now, it would be an evolutionary miracle, like finding an island of humans who could be taught to fly. If an animal had a capacity as biologically advantageous as language but somehow hadn’t used it until now, it would be an evolutionary miracle, like finding an island of humans who could be taught to fly. Biology Noam Chomsky The biolinguistic enterprise: where does it stand today? 3:00pm - Dec. 11, 2007 MIT BCS 46-3310 http://www.law.georgetown.edu/faculty/mikhail/documents/Noam_Chomsky_Biolinguistic_Explorations.pd f

8. A Comparative Approach Can knowing how animals (non-human primates) communicate inform us about the evolution of language? Can knowing how animals (non-human primates) communicate inform us about the evolution of language?

9. What’s different? Human Big vocabulary Big vocabulary Arbitrary form-meaning Arbitrary form-meaning Compositionality Compositionality Ability to attribute mental state: Ability to attribute mental state: –Informing –Deceiving –Teaching Animal Communication Small vocabulary Small vocabulary Non-arbitrary form-meaning Non-arbitrary form-meaning Virtually no compositionality Virtually no compositionality Poor (or lack of) ability to attribute mental state Poor (or lack of) ability to attribute mental state

10. Spontaneous communication among non-human primates limited to a small repertoire of signals limited to a small repertoire of signals whose categories are built in whose categories are built in –meanings change a bit according to the environment reference is immediate, not displaced reference is immediate, not displaced just like “lower” animals just like “lower” animals –including some invertebrates Slide from Liberman

11. With Training many creatures can be taught to makes sounds or gestures many creatures can be taught to makes sounds or gestures –when they see a “referent” or when they want something. It’s even easier for them to learn to associate particular sounds, gestures or icons with (types of) objects. It’s even easier for them to learn to associate particular sounds, gestures or icons with (types of) objects. This can look a lot like human speech communication: This can look a lot like human speech communication: –but such abilities make it all the stranger that other speech-like communication systems haven’t evolved. Relationship of this kind of operant conditioning to human linguistic behavior is controversial Relationship of this kind of operant conditioning to human linguistic behavior is controversial Slide from Liberman

12. Rhesus macaque mother, Japanese macaque infant Japanese macaque mother, Rhesus macaque infant Owren, M. J., J. A. Dieter, R. M. Seyfarth and D. L. Cheney (1992). Control Children: Mainly COOS Foster Children: Control Children: COOS & GRUFFS Foster Children: Mainly COOS COOS & GRUFFS (mid) Limited Repertoire of Signals (hardwired) Animal Communication Systems

13. Production and Perception Asymmetry Limited Repertoire in Production Limited Repertoire in Production But greater comprehension ability But greater comprehension ability Cross-fostered monkey produce own species signal and not foster parents. Cross-fostered monkey produce own species signal and not foster parents. i.e., limited productive vocabulary, yet can understand others’ calls. i.e., limited productive vocabulary, yet can understand others’ calls. Why is the speaker not tailoring signal to the one used by listener? Why is the speaker not tailoring signal to the one used by listener? If tailoring (thinking about what others know & what others know about what you know): If tailoring (thinking about what others know & what others know about what you know): –You call this “blicket.” If next time I call it “blicket,” perhaps you’ll know that I am referring to the same thing.

14. Speaker Listener It’s cold in here!!! Harry probably means for me to close the door. Communication and Mind Reading

15. Leopard… Receiver - “Listener” Leopard here… gotta hide up in the tree Signaler - “Speaker”

16. Ahhhhh…….. Signaler - “Speaker” You: Receiver - “Listener” Something must have happened in the house

17. Intentions of the Animal Signaling Dennett (1987) Zero-order intentional system: Zero-order intentional system: –Signaler has no beliefs or desires. –The animal only display involuntary, automatic responses in front of different types of danger and different escape strategies in front of different acoustic stimuli. First-order intentional system: First-order intentional system: –Signaler has beliefs and desires (but not beliefs about beliefs). –Calls have some meaning. –E.g., A call “there is a snake around” may express the belief that there is one around (content oriented) or it may express the desire that the audience follows escape strategy x (goal oriented). Second or higher order intentional system: Second or higher order intentional system: –Signaler has some conception of their own mind and of the mental states in others’ minds. –E.g., A call “there is a snake around” may be given not because the caller believes so, but because he wants the others to believe that it is so.

18. Some questions about animal communication systems Are signalers’ calls ‘triggered’ by specific events? Are signalers’ calls ‘triggered’ by specific events? –Are calls involuntary or voluntary? Do signalers call because they want to cause behavioral change in the listeners which they notice to be contingent upon calling? Do signalers call because they want to cause behavioral change in the listeners which they notice to be contingent upon calling? Do speakers call with the intent of informing ignorant listeners? Do speakers call with the intent of informing ignorant listeners? What do listeners understand from speakers’ calls? What do listeners understand from speakers’ calls?

19. Are signalers’ calls ‘triggered’ by specific events? Are signalers’ calls ‘triggered’ by specific events? –Emotional Reaction to Event? –Or Audience Design? Experiment: Experiment: 1. Play sound of leopard growls within earshot of an individual monkey. OR Use dummy leopard within field of vision of an individual monkey. 2.Test individual in several conditions (e.g.): b. While individual is not alone and already in tree. a. While individual is alone and is already in tree. 3. Compare likelihood to alarm call in the various conditions. Alarm call good for the audience, potentially bad for the one calling – attracting attention of predator. Will the individual call less if alone than if there is an audience present?

20. Emotional Response vs. Audience Design Are signalers’ calls ‘triggered’ by specific events? Are signalers’ calls ‘triggered’ by specific events? Some evidence suggest the calls are not involuntary (Cheney & Seyfarth) Some evidence suggest the calls are not involuntary (Cheney & Seyfarth) –Females call more for kin than non-kin present –Males call more with female than with another male –High-rank vervets call more often than subordinates Animal Communication Systems

21. Do signalers call because they want to cause behavioral change in the listeners which they notice to be contingent upon calling? Do signalers call because they want to cause behavioral change in the listeners which they notice to be contingent upon calling? Do speakers call with the intent of informing ignorant listeners? Do speakers call with the intent of informing ignorant listeners? Possible Experiment: Possible Experiment: If mom is aware of offspring’s mental state mom should call more when offspring ignorant. 1.Introduce predator or food to mother in two conditions a.In the presence of offspring (offspring informed condition) b.In the absence of offspring (offspring uninformed condition) 2.Offspring present for both conditions now. vs. 3. Compare likelihood to call for 1(a) vs. 1(b).

22. Do signalers call because they want to cause behavioral change in the listeners which they notice to be contingent upon calling? Do signalers call because they want to cause behavioral change in the listeners which they notice to be contingent upon calling? Do speakers call with the intent of informing ignorant listeners? Do speakers call with the intent of informing ignorant listeners? Moms do not call more when offspring ignorant than when offspring not ignorant. You would think they would call in the case of the predator, but they don’t!!! vs. But see: PBS Animal Einsteins: Thinking about Thinking http://vvi.onstreammedia.com/cgi-bin/visearch?user=pbs- saf&template=play220asf.html&query=Animal+Einsteins&squery=%2BClipID%3A7+%2BVideoAsset%3Apbssaf903&inputField=undefined&ccstart=2 663400&ccend=3295300&videoID=pbssaf903

23. Onishi & Baillargeon (2005) Infants watch as actor takes object, plays, puts in green box. [Pause, curtain] Actor reaches into green box as if to take object. [Pause, curtain] Belief induction trial: e.g., False Belief (unseen switch): infant but not actor sees object move from green to yellow box. Test trial: e.g., actor reaches into yellow box. [Pause until trial ends]

24. Other belief induction trials: Other belief induction trials: –True belief (seen switch): actor watches as object moves from green to yellow. –True belief (no switch): actor watches as yellow box moves but object does not come out of green box –False belief (one seen, then one unseen switch): actor watches as object moves from green to yellow, then does not watch as object moves back to green. –Test trial: for half the infants actor reached to yellow and for half reached to green box. Results Results –In each of the four conditions, infants looked longer during the test when the actor reached to the location that was inconsistent with where she thought the object was (where she correctly or falsely believed - ? – it to be).  False belief understanding in 15-month-olds??

25. Mental State Attribution The ability to The ability to –Attribute mental states –Attribute mental states attribute mental states like ignorance, motives, beliefs to others – –recognize that your own beliefs, motives, emotions can be different from other individuals’ Mental state attribution permits informing, deception, teaching

26. http://vvi.onstreammedia.com/cgi- bin/visearch?user=pbs- saf&template=play220asf.html&query=%2A &squery=%2BClipID%3A2+%2BVideoAsset %3Apbssaf1504&inputField=%20&entire=N o&ccstart=89502&ccend=1088861&videoID =pbssaf1504 http://vvi.onstreammedia.com/cgi- bin/visearch?user=pbs- saf&template=play220asf.html&query=%2A &squery=%2BClipID%3A2+%2BVideoAsset %3Apbssaf1504&inputField=%20&entire=N o&ccstart=89502&ccend=1088861&videoID =pbssaf1504 http://vvi.onstreammedia.com/cgi- bin/visearch?user=pbs- saf&template=play220asf.html&query=%2A &squery=%2BClipID%3A2+%2BVideoAsset %3Apbssaf1504&inputField=%20&entire=N o&ccstart=89502&ccend=1088861&videoID =pbssaf1504 http://vvi.onstreammedia.com/cgi- bin/visearch?user=pbs- saf&template=play220asf.html&query=%2A &squery=%2BClipID%3A2+%2BVideoAsset %3Apbssaf1504&inputField=%20&entire=N o&ccstart=89502&ccend=1088861&videoID =pbssaf1504 Main point: Imitation, No teaching. Lacking cooperative behavior. Main point: Imitation, No teaching. Lacking cooperative behavior.