ProfessorPaulBloom:
Thisclasstodayisaboutlanguage.Andlanguageis,toalargeextent,wheretheactionis.Thestudyofhumanlanguagehasbeenthebattlegroundoverdifferenttheoriesofhumannature.So,everyphilosopherorpsychologistorhumanistorneuroscientistwhohaseverthoughtaboutpeoplehashadtomakesomeclaimaboutthenatureoflanguageandhowitworks.I'mincludingherepeoplelikeAristotleandPlato,Hume,Locke,FreudandSkinner.I'malsoincludingmodern-dayapproachestocomputationaltheory,cognitiveneuroscience,evolutionarytheoryandculturalpsychology.Ifyouhopetomakeitwithatheoryofwhatpeopleareandhowpeoplework,youhavetoexplainandtalkaboutlanguage.Infact,languageissufficientlyinterestingthat,unlikemostotherthingsI'lltalkaboutinthisclass,thereisanentirefielddevotedtoitsstudy,thefieldoflinguisticsthatisentirelydevotedtostudyingthenuancesandstructuresofdifferentlanguages.
Now,I'llfirst,beforegettingintodetails,makeadefinitionalpoint.WhenI'mtalkingaboutlanguageI'mmeaningsystemslikeEnglishandDutchandWarlpiriandItalianandTurkishandUrduandwhatwe'veseenandheardrightnowinclassinthedemonstrationthatprecededtheformallecture.[Beforeclassstarted,ProfessorBloomhadseveralbilingualstudentsgivedemonstrationsofnon-Englishspeech.]Now,youcoulduselanguageinadifferentsense.Youcouldusetheterm"language"todescribewhatdogsdo,orwhatchimpanzeesdo,orbirds.Youcoulduselanguagetodescribemusic,talkaboutthe--amusicallanguageorart,oranycommunicativesystem,andthere'sactuallynothingwrongwiththat.There'snoruleabouthowyou'resupposedtousetheword"language."Buttheproblemisifyouusetheword"language"impossibly,incrediblybroadly,thenfromascientificpointofviewitbecomesuselesstoaskinterestingquestionsaboutit.IflanguagecanrefertojustabouteverythingfromEnglishtotrafficsignals,thenwe'renotgoingtobeabletofindinterestinggeneralizationsordogoodscienceaboutit.
So,whatIwanttodois,Iwanttodiscussthescientificnotionoflanguage,atfirstrestrictingmyselftosystemslikeEnglishandDutchandAmericansignlanguageandNavajoandsoon.Oncewe'vemadesomegeneralizationsaboutlanguageinthisnarrowsense,wecouldthenask,andwewillask,towhatextentdoothersystemssuchasanimalcommunicationsystemsrelatetothisnarrowerdefinition.Sowecouldask,inthisnarrowsense,whatpropertiesdolanguageshaveandthengoontoask,inabroadersense,whatothercommunicativesystemsalsopossessthoseproperties.
Well,somethingsareobviousaboutlanguagesoherearesome;herearethequestionswewillask.Thiswillframeourdiscussiontoday.We'llfirstgooversomebasicfactsaboutlanguage.We'lltalkaboutwhatlanguagesshare,we'lltalkabouthowlanguagedevelops,andwe'lltalkaboutlanguageandcommunicationinnonhumans.
Ibeganthisclasswithademonstrationof--thatillustratestwoveryimportantfactsaboutlanguage.Oneisthatlanguagesallsharesomedeepandintricateuniversals.Inparticular,alllanguages,atminimum,arepowerfulenoughtoconveyanabstractnotionlikethis;abstractinthesensethatittalksaboutthoughtsandittalksaboutapropositionandspatialrelationsinobjects.There'snolanguageintheworldthatyoujustcannottalkaboutabstractthingswith.Everylanguagecandothis.Butthedemonstration[beforeclass]alsoillustratedanotherfactaboutlanguage,whichishowdifferentlanguagesare.Theysounddifferent.Ifyouknowonelanguage,youdon'tnecessarilyknowanother.It'snotmerelythatyoucan'tunderstandit.Itcouldsoundstrangeorlookunusualinthecaseofasignlanguage.Andso,anyadequatetheoryoflanguagehastoallowforboththecommonalitiesandthedifferencesacrosslanguages.Andthisisthepuzzlefacedbythepsychologyandcognitivescienceoflanguage.
Well,let'sstartwithaninterestingclaimaboutlanguagemadebyCharlesDarwin.So,Darwinwrites,"Manhasaninstinctivetendencytospeak,asweseeinthebabbleofouryoungchildren,whilenochildhasaninstinctivetendencytobake,breworwrite."AndwhatDarwinisclaiminghere,andit'sacontroversialandinterestingclaim,isthatlanguageisspecialinthatthere'ssomesortofpropensityorcapacityorinstinctforlanguageunliketheotherexampleshegives.NoteverythingcomesnaturaltousbutDarwinsuggeststhatlanguagedoes.
Well,whyshouldwebelievethis?
Well,therearesomebasicfactsthatsupportDarwin'sclaim.Foronething,everynormal--everyhumansocietyhaslanguage.Inthecourseoftraveling,culturesencounterotherculturesandtheyoftenencounterculturesthatareverydifferentfromtheirown.Butthroughthecourseofhumanhistory,nobodyhaseverencounteredanothergroupofhumansthatdidnothavealanguage.Doesthisshowthatit'sbuiltin?
Well,notnecessarily.Itcouldbeaculturalinnovation.Itcouldbe,forinstance,thatlanguageissuchagoodideathateveryculturecomesacrossitanddevelopsit.Justabouteverycultureusessomesortofutensilstoeatfoodwith,aknifeandafork,chopsticks,aspoon.Thisprobablyisnotbecauseuseofeatingutensilsishumannature,butrather,it'sbecauseit'sjustaveryusefulthingthatculturesdiscoveroverandoveragain.Well,weknowthatthisprobablyisnottruewithregardtolanguage.Andonereasonweknowthisisbecauseofthedemonstratedcasestudieswherealanguageiscreatedwithinasinglegeneration.Andthesecasestudieshavehappenedoverhistory.
Thestandardexampleispeopleinvolvedintheslavetrade.Theslavetraderevolvingaroundtobaccoorcottonorcoffeeorsugarwouldtendtomixslavesandlaborersfromdifferentlanguagebackgrounds,inpartdeliberately,soastoavoidthepossibilityofrevolt.Whatwouldhappenisthesepeoplewhowereenslavedfromdifferentcultureswoulddevelopamakeshiftcommunicationsystemsotheycouldtalktooneanother.Andthisiscalleda"pidgin,"p-i-d-g-i-n,apidgin.Andthispidginwashowtheywouldtalk.Andthispidginwasnotalanguage.Itwasstringsofwordsborrowedfromthedifferentlanguagesaroundthemandputtogetherinsortofhaphazardways.
Thequestioniswhathappenstothechildrenwhoareraisedinthissociety.Andyoumightexpectitthattheywouldcometospeakapidgin,buttheydon't.Whathappensis,inthecourseofasinglegeneration,theydeveloptheirownlanguage.Theycreatealanguagewithrichsyntaxandmorphologyandphonology,termsthatwe'llunderstandinafewminutes.Andthislanguagethattheycreateiscalleda"creole."Andlanguagesthatweknownowascreoles,thewordrefersbacktotheirhistory.Thatmeansthattheyweredevelopedfrompidgins.Andthisisinterestingbecausethissuggeststhattosomeextenttheabilitytouseandunderstandandlearnlanguageispartofhumannature.Itdoesn'trequireanextensiveculturalhistory.Rather,justaboutanynormalchild,evenwhennotexposedtoafull-fledgedlanguage,cancreatealanguage.
Andmorerecently,there'sbeencasestudiesofchildrenwhoacquiresignlanguage.There'sawonderfulcaseinNicaraguainsignlanguagewheretheyacquiresignlanguagefromadultswhothemselvesarenotversedinsignlanguage.They'resortofsecond-languagelearnersstrugglingalong.Whatyoumighthaveexpectedwouldbethechildrenwouldthenusewhateversystemtheiradultsuse,buttheydon't.They"creolized"it.Theytakethismakeshiftcommunicationsystemdevelopedbyadultsand,again,theyturnitintoafull-blownlanguage,suggestingthattosomeextentit'spartofourhumannaturetocreatelanguages.
Also,everynormalhumanhaslanguage.Noteverybodyinthisroomcanrideabicycle.Noteverybodyinthisroomcanplaychess.Buteverybodypossessesatleastonelanguage.Andeverybodystartedtopossessatleastonelanguagewhentheywereachild.Thereareexceptions,buttheexceptionscomeaboutduetosomesortofbraindamage.Anyneurologicallynormalhumanwillcometopossessalanguage.
Whatelsedoweknow?
Well,theclaimthatlanguageispartofhumannatureissupportedbyneurologicalstudies,someofwhichwerereferredtointhechaptersonthebrainthatyoureadearlierthattalkaboutdedicatedpartsofthebrainthatworkforlanguage.Andifpartsofthesebrains--ifparts--ifthesepartsofthebrainaredamagedyougetlanguagedeficitsoraphasiaswhereyoumightlosetheabilitytounderstandorcreatelanguage.Morespeculatively,therehasbeensomefairlyrecentworkstudyingthegeneticbasisoflanguage,lookingatthegenesthataredirectlyresponsibleforthecapacitytolearnanduselanguage.Andonebitofevidencethatthesegenesareimplicatedisthatsomeunfortunatepeoplehavepointmutationsinthesegenes.Andsuchpeopleareunabletolearnanduselanguage.
So,ingeneral,thereissomesupport,atleastataverybroadlevel,fortheclaimthatlanguageisinsomesensepartofhumannature.Well,whatdowemeanbylanguage?
Whatarewetalkingaboutwhenwetalkaboutlanguage?
Wedon'twanttorestrictourselves,forinstance,toEnglishorFrench.Whatdoalllanguagesshare?
Well,alllanguagesarecreativeandthismeansacoupleofthings.
OnemeaningisthemeaningemphasizedbyReneDescartes.WhenReneDescartesarguedthatwearemorethanmerelymachines,hisbestpieceofevidenceforhimwasthehumancapacityforlanguage.Nomachinecoulddothisbecauseourcapacityforlanguageisunboundedandfree.Wecouldsayanythingwechoosetos
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