IELTS雅思阅读真题.docx

IELTS雅思阅读真题.docx

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IELTS雅思阅读真题

IELTS雅思阅读真题

　　蚂蚁智力

　　Collectiveintelligence:

：

Antsandbrain'sneurons

　　STANFORD-Anindividualantisnotverybright,butantsinacolony,operatingasacollective,doremarkablethings.

　　Asingleneuroninthehumanbraincanrespondonlytowhattheneuronsconnectedtoitaredoing,butallofthemtogethercanbeImmanuelKant.

　　ThatresemblanceiswhyDeborahM.Gordon,StanfordUniversityassistantprofessorofbiologicalsciences,studiesants.

　　"I'minterestedinthekindofsystemwheresimpleunitstogetherdobehaveincomplicatedways,"shesaid.

　　Noonegivesordersinanantcolony,yeteachantdecideswhattodonext.

　　Forinstance,anantmayhaveseveraljobdescriptions.Whenthecolonydiscoversanewsourceoffood,anantdoinghousekeepingdutymaysuddenlybecomeaforager.Orifthecolony'sterritorysizeexpandsorcontracts,patrollerantschangetheshapeoftheirreconnaissancepatterntoconformtothenewrealities.Sincenooneisinchargeofanantcolony-includingthemisnamed"queen,"whichissimplyabreeder-howdoeseachantdecidewhattodo?

　　Thiskindofundirectedbehaviorisnotuniquetoants,Gordonsaid.Howdobirdsflyinginaflockknowwhentomakeacollectiverightturn?

Allanchoviesandotherschoolingfishseemtoturninunison,yetnoonefishistheleader.

areexploringvaries.

　　"Theantsaregoodatfindingnewplacestoliveinandgoodatfindingfood,"Gordonsaid."We'reinterestedinfindingouthowtheydoit."

　　HerantsareconfinedbyPlexiglaswallsandanastyglue-likesubstancealongthetopsoftheboardsthatkeepstheantsinside.Shemovesthewallsinandouttochangethearenaandvideotapestheants'movements.Acomputertrackseachantfromitsimageonthetapeandreadsitspositionsoshehasadiagramoftheants'activities.

　　Themotionsoftheantsconfirmtheexistenceofacollective.

　　"Acolonyisanalogoustoabrainwheretherearelotsofneurons,eachofwhichcanonlydosomethingverysimple,buttogetherthewholebraincanthink.Noneoftheneuronscanthinkant,butthebraincanthinkant,thoughnothinginthebraintoldthatneurontothinkant."

　　Forinstance,antsscoutforfoodinaprecisepattern.Whathappenswhenthatpatternnolongerfitsthecircumstances,suchaswhenGordonmovesthewalls?

　　"Antscommunicatebychemicals,"shesaid."That'showtheymostlyperceivetheworld;theydon'tseeverywell.Theyusetheirantennaetosmell.Sotosmellsomething,theyhavetogetveryclosetoit.

　　"Thebestpossiblewayforantstofindeverything-ifyouthinkofthecolonyasanindividualthatistryingtodothis-istohaveananteverywhereallthetime,becauseifitdoesn'thappenclosetoanant,they'renotgoingtoknowaboutit.Ofcourse,therearenotenoughantsinthecolonytodothat,sosomehowtheantshavetomovearoundinapatternthatallowsthemtocoverspaceefficiently."

　　Keepinginmindthatnooneisinchargeofacolonyandthatthereisnocentralplan,howdotheantsadjusttheirreconnaissanceiftheirterritoryexpandsorshrinks?

　　"Noanttoldthem,'OK,guys,ifthearenais20by20....'Somehowtherehastobesomerulethatindividualantsuseindecidingtochangetheshapeoftheirpathssotheycovertheareaseffectively.Ithinkthatthatruleistherateinwhichtheybumpintoeachother."

　　Themorecrowdedtheyare,themoreofteneachantwillbumpintoanotherant.Iftheareaoftheirterritoryisexpanded,thefrequencyofcontactdecreases.Perhaps,Gordonthinks,eachanthasathresholdfornormalityandadjustsitspathshapedependingonhowoftenthenumberofencountersexceedsorfallsshortofthatthreshold.

　　Iftheterritoryshrinks,thenumberofcontactsincreasesandtheantaltersitssearchpattern.Ifitexpands,contactdecreasesanditaltersthepatternadifferentway.

　　IntheArizonaharvesterants,Gordonstudiestasksbesidespatrolling.Eachanthasajob.

　　"Idividethetasksintofour:

foraging,nestmaintenance,midden[pilingrefuse,includinghusksofseeds]andpatrolling-patrollersaretheonesthatcomeoutfirstinthemorningandlookforfood.Theforagersgowherethepatrollersfindfood.

　　"Thecolonyhasabouteightdifferentforagingpaths.Everydayitusesseveralofthem.Thepatrollersgooutfirstonthetrailsandtheyattracteachotherwhentheyfindfood.Bytheendofanhour'spatrolling,mostpatrollersareonjustafewtrails....Alltheforagershavetodoisgowheretherearethemostpatrollers."

　　Eachanthasitsprescribedtask,buttheantscanswitchtasksifthecollectiveneedsit.Anantonhousekeepingdutywilldecidetoforage.NoonetoldittodosoandGordonandotherentomologistsdon'tknowhowthathappens.

　　"Noantcanpossiblyknowhowmuchfoodeverybodyiscollecting,howmanyforagersareneeded,"shesaid."Ananthastohaveverysimplerulesthattellit,'OK,switchandstartforaging.'Butanantcan'tassessgloballyhowmuchfoodthecolonyneeds.

　　"I'vedoneperturbationexperimentsinwhichImarkedantsaccordingtowhattaskthey'redoingonagivenday.Theantsthatwereforagingforfoodweregreen,thosethatwerecleaningthenestwereblueandsoon.ThenIcreatedsomenewsituationintheenvironment;forexample,IcreateamessthatthenestmaintenanceworkershavetocleanuporI'llputoutextrafoodthatattractsmoreforagers.

　　"Itturnsoutthatantsthatweremarkeddoingacertaintaskonedayswitchtodoadifferenttaskwhenconditionschange."

　　Ofabout8,000speciesofants,onlyabout10percenthavebeenstudiedthusfar.

　　"It'shardtogeneralizeanythingaboutthebehaviorofants,"Gordonsaid."Mostofwhatweknowaboutantsistrueofavery,verysmallnumberofspeciescomparedtothenumberofspeciesoutthere."

天才儿童

　　TIME:

5-7'

　　HOWIQBECOMESIQ

　　In1904theFrenchministerofeducation,facinglimitedresourcesforschooling,soughtawaytoseparatetheunablefromthemerelylazy.AlfredBinetgotthejobofdevisingselectionprinciplesandhisbrilliantsolutionputastamponthestudyofintelligenceandwastheforerunnerofintelligencetestsstillusedtoday.Hedevelopedathirty-problemtestin1905,whichtappedseveralabilitiesrelatedtointellect,suchasjudgmentandreasoning.Thetestdeterminedagivenchild'smentalage'.Thetestpreviouslyestablishedanormforchildrenofagivenphysicalage.Forexample,five-year-oldsonaveragegettenitemscorrect,therefore,achildwithamentalageoffiveshouldscore10,whichwouldmeanthatheorshewasfunctioningprettymuchasothersofthatage.Thechild'smentalagewasthencomparedtohisphysicalage.

　　Alargedisparityinthewrongdirection（e.g.,achildofninewithamentalageoffour）mightsuggestinabilityratherthanlazinessandmeansthatheorshewasearmarkedforspecialschooling.Binet,however,deniedthatthetestwasmeasuringintelligenceandsaidthatitspurposewassimplydiagnostic,forselectiononly.Thismessagewashoweverlostandcausedmanyproblemsandmisunderstandingslater.

　　AlthoughBinet'stestwaspopular,itwasabitinconvenienttodealwithavarietyofphysicalandmentalages.So,in1912,WilhelmSternsuggestedsimplifyingthisbyreducingthetwotoasinglenumber.Hedividedthementalagebythephysicalageandmultipliedtheresultby100.Anaveragechild,irrespectiveofage,wouldscore100.anumbermuchlowerthan100wouldsuggesttheneedforhelpandonemuchhigherwouldsuggestachildwellaheadofhispeer.

　　ThismeasurementiswhatisnowtermedtheIQ（intelligencequotient）scoreandithasevolvedtobeusedtoshowhowaperson,adultorchild,performedinrelationtoothers.ThetermIQwascoinedbyLewism.Terman,professorofpsychologyandeducationofStanfordUniversity,in1916.HehadconstructedanenormouslyinfluentialrevisionofBinet'stest,calledtheStanford-Binettest,versionsofwhicharestillgivenextensively.

　　Thefieldstudyingintelligenceanddevelopingtestseventuallycoalescedintoasub-fieldofpsychologycalledpsychometrics（psychofor‘mind'andmetricsfor'measurements'）.Thepracticalsideofpsychometrics（thedevelopmentanduseoftests）becamewidespreadquiteearly,by1917,whenEinsteinpublishedhisgrandtheoryofrelativity,mass-scaletestingwasalreadyinuse.

　　Germany'sunrestrictedsubmarinewarfare（whichledtothesinkingoftheLusitaniain1915）provokedtheUnitedStatestofinallyenterthefirstworldwarinthesameyear.Themilitaryhadtobuildupanarmyveryquicklyandithadtwomillioninducteestosortout.Whowouldbecomeofficersandwhoenlistedmen?

Psychometriciansdevelopedtwointelligenceteststhathelpedsortallthesepeopleout,atleasttosomeextent.Thiswasthefirstmajoruseoftestingtodecidewholivedandwhodiedsinceofficerswerealotsaferonthebattlefield.Theteststhemselvesweregivenunderhorrendouslybadconditionsandtheexaminersseemedtolackcommonsense.Alotofrecruitssimplyhadnoideawhattodoandinseveralsessionsmostinducteesscoredzero!

TheexaminersalsocameupwiththequiteastoundingconclusionfromthetestingthattheaverageAmericanadult'sintelligencewasequaltothatofathirteen-year-old!

　　Nevertheless,theabilityforvariousauthoritiestoclassifypeopleonscientificallyjustifiablepremiseswastooconvenientandsignificanttobedismissedlightly,sowithallgoodastoundingintentionsandoftenoverenthusiasm,society'saffinityforpsychologicaltestingproliferated.

　　BackinEurope,SirCyrilBurt,professorofpsychologyatUniversityCollegeLondonfrom1931to1950,wasaprominentfigureforhis