心理学专业知识讲座

Evolution,Psychology,EvolutionaryPsychologyandHumanUniquenessMScPsychologicalResearchMethodsPSYC073PEpistemologyandPhilosophyofScienceDecember12th2023StephenWalker1/142Overview Therewillinevitablybesomeoverlapwithnature/nurtureissues(Dec5th)Thereisalsoaacontrastbetweenevolutionaryorbiologicalpsychologyandsocialconstructionistorpsychosocialapproaches(Nov28th)Atleasttwokindsofreductionismwillbeillustrated:explainingbehavioursasadaptations,andexplainingbehavioursintermsofneuralcircuitsthatcontrolthem.2/142Outline Iwillstartoffbylookingatanimalbehaviour,whereevolutionhasrelevance.“EvolutionaryPsychology”isbasedontheclaimthathumanpsychologyisstronglydeterminedbyhumanevolution.Theevidencefortheseclaimsisoftenextremelyweak,butIwilllookatafewrecentexamples.Iwillalsolookbrieflyattheevidenceconcerningthecourseofhumanevolution.3/142PaperHandout*NB*thepaperhandoutincludesonlyasmallfractionoftheslidesinthispresentation:apdfofmostoftheslideswillbeavailableontheintranetThepaperhandoutincludesalistofalternativebooksonhumanevolutionwhichareinBKlibraryonpage6Anypiecesofworkmentionedinthepresentationshouldhaveitscitationlistedonpages7&8ofthehandout.4/142FossilsversusGenomicsThereareepistemologicaldifficultiesinstudyinghumanevolution.Thedifficultiesareininferringthepastcourseofhumanevolutionfromalimitednumberoffossilfinds.Butinthelast10or15yearstechnologieshavebecomeavailableallowinggeneticiststopinpointwhereandwhenthehumangenomehasundergonesignificantchanges.5/142EvolutionandDNAThereisahugeamountofinformationpertinenttoevolutionproducedbyrecenttechnologies:thesearecitationsforthepaperbyAltschuletal.(1990)aboutasearchtoolforDNAandproteinsequencedatabasesWikipediasaysthiswasthemostwidelycitedofallscientificpaperspublishedinthe1990s6/142GenomicsandBioinformaticsDNAsequencing,inchumanandchimpanzeeGenesplicingandgeneticengineeringGeneexpressiondatafrom‘Microarrays’7/142TheDarwinianTheoryofEvolution−“DescentwithModification” ThereareinheriteddifferencesbetweenindividualsTheseincluderandomvariationsResourcesarenotunlimitedSomeindividualswillflourishmorethanothersandproducemoreoffspringNaturalselectionoccursifapopulationchangesovergenerationsbecauseofthis8/142Evolution—II Thefirstpointaboutevolutionisthatitconnectsthehumanspecieswiththerestoftheanimalkingdom,However,itisalsopossibleandindeedlikelythatthecourseofhumanevolutionhasledtohumansbeinguniquelydifferentfromallothercurrentlylivingspecies9/142Almostallhumanbehaviourinvolvesculturallearning(TomaselloandRazoksky,2023;Tomaselloetal.,2023)Almostallanimalbehaviourisgeneticallypre-programmed(byevolution)tofitanecologicalniche(Darwin,1859;Tinbergen,1951;ManoliandBaker,2023)HumanUniquenessonbehaviouralgrounds10/142Darwin(1859)TheOriginofSpeciesChapVII“Instinct”.Notdefined,butthreemainexamplesTheinstinctofthefemalecuckootolaysmalleggsinotherbird’snests,andtheegg-ejectionbehaviorofthenewlyhatchedcuckoochick;Slave-makinginstinctsinsomespeciesofantThecell-makinginstinctofthehoneybeeThebehaviorswereseenbyDarwinasnotnecessarilydependentonanatomicalcharacteristics11/142DarwinonHoneybeesDarwinthoughtthatthehoneycombwas“absolutelyperfectineconomisinglabourandwax”onthegroundsofgeometry.Butitalso“canbeexplainedbynaturalselectionhavingtakenadvantageofnumerous,successive,slightmodificationsofsimplerinstincts”.Thesewerebasedonspheresasinbumblebees,withS.Americanstinglessbeesintermediate.NBthousandsofsolitarybeeswhichdonotstorehoney12/142AnotherofDarwin’sexamples:cuckoos13/142AnotherofDarwin’sexamples:cuckoos14/142Darwin(1859)page185functionandform

.uk“….theacutestobserverbyexaminingthedeadbodyofthewater-ouzelwouldneverhavesuspecteditssub-aquatichabits;yetthisanomalousmemberofthestrictlyterrestrialthrushfamilywhollysubsistsbydiving,—graspingthestoneswithitsfeetandusingitswingsunderwater.”Actuallyhassomeanatomicaladaptations:3rdeyelid,nostrilflapsandoilgland10timeslargerthannon-aquaticperchingbirds.ButVoelker(2023)agreesthatthethrushistheclosestrelativeandsuggestthatdippersdivergedonly4myearsbp15/142Darwin(1859)page185

.ukAndthebehaviouraladaptationwouldhavecomefirst−Thrushesforaginginstreamsinsteadofsolidgroundwouldthenfindenlargedoilglandsuseful16/142DipperdietincludesaquaticinsectlarvaeCaddisflylarvaebuildthemselvescases,invariouswaysdependingonthespecies.TheDarwinianpositionwouldbethattheyinheritthebehavioursrequiredforthistask.ButinfactStuartandCurrie(2023)foundthattherewaslittlerelationbetweenthetypesofbehavioursandthestructuralend-productacrossavarietyofspecies.Dospeciesneeda‘geneticblueprint’fortheend-product?17/14218/14219/142Evolutionconnectsthehumanspecieswiththerestoftheanimalkingdom

20/142Period,begins(MillionYears)EraQuaternary

Holocene 0,01 Pleistocene 1.6Tertiary

Pliocene 5 Miocene 23 Oligocene 35 Eocene 56 Paleocene 65Cretaceous 145Jura 210Trias 250Permian 290Carboniferous 360Devonian 410Silurian 440Ordovician 505Cambrian 545Proterozoic 2500Archean 3800PrecambrianPaleozoicMesozoicCenozoicOldestfossilsofcomplexanimalsCreationofextantphylaManDinosaursReptiles,birds,mammals(Amniotes)PrimitivefishFirstbacteriaFirstmulticellularorganisms21/14222/14223/14224/142Lappinetal.,2023;standardtexts25/142EVOLUTIONARILYCONSERVEDMOLECULARGENETICMECHANISMSFORPATTERNINGTHEEMBRYONICBRAIN.Reichert,H.,&Simeone,A.(2023)

FlymutantrestoredwithhumangeneFlymutantrestoredwithmousegeneMousemutantrestoredwithflygene26/142Bishopetal.,202327/142Ethologicalanalysesofanimalbehaviour Vitalistsbelievedintheinstinctsasmystical….andbehaviouristswerepreoccupiedwithlearning…thewayoutwasfocussingonthesurvivalvalueofbehaviourpatterns.“Behaviourpatternsbecomeexplicablewheninterpretedastheresultofnaturalselection,analogouswithanatomicalandphysiologicalcharacteristics.”28/142Tinbergen 29/1421951,titleandfrontispiece 30/142Genomenewsnetwork31/142Zig-zagdance32/142Experimentalstimulusvariation33/142AStudyofInstinct

1951Thereisnoentryforgeneinthe1951indexButinstinctand“innate”arethethemes,andreferstogeneticsandmutationsinthechapteron“TheEvolutionofBehaviour”Tinbergenincludedsomeill-advisedevolutionarypsychologyButthereisacasethatexplanationsforsticklebackandhumanbehaviourshouldbefundamentallydifferent.34/142Instinct-2Tinbergen(1951)stressedtwokeyconcepts1.“signstimuli”e.g.rednessforsticklebacks.2.The“innatereleasingmechanism”,bywhichparticularsignstimulireleaseparticularinstinctivebehaviourpatternsHebelievedtheseconceptsappliedtomammalsButtheevidenceismuchclearerwithlowervertebratesandinvertebrates35/142E.g.SpidersTheorbwebAfirstattempt36/142e.g.spiders237/142Darwin’scommentonspiders“Thuseverywhereinnaturearebattle,craft,andingenuity,allfollowingthemercilesslawofegoism,inordertomaintaintheirownlivesandtodestroythoseofothers”CharlesDarwinwritinginAnimalIntelligencebyG.J.Romanes(1882),commentingonwolfandtrapdoorspiders,p.21338/142Innatebehaviourse.g.fruitflycourtshipKimura,K.I.,Ote,M.,Tazawa,T.,&Yamamoto,D.(2023).FruitlessspecifiessexuallydimorphicneuralcircuitryintheDrosophilabrain.Nature,438(7065),229-233.

“…..weidentifyasubsetoffru-expressinginterneuronsinthebrainthatshowmarkedsexualdimorphismintheirnumberandprojectionpattern…….Fruexpressioncanproduceamale-specificneuralcircuit,”“Throughouttheanimalkingdomtheinnatenatureofbasicbehaviourroutinessuggeststhattheunderlyingneuronalsubstratesnecessaryfortheirexecutionaregeneticallydeterminedanddevelopmentallyprogrammed”Manoli&Baker(2023).39/142e.g.fruitflyaggressionVrontouetal.,(2023)fruitlessregulatesaggressionanddominanceinDrosophilaNatureNeuroscience,9,(01Dec2023),1469-1471

Whencompetingforresources,twofliesofthesamesexfighteachother.Malesandfemalesfightwithdistinctlydifferentstyles,andmalesbutnotfemalesestablishdominancerelationships.Hereweshowthatsex-specificsplicingofthefruitlessgeneplaysacriticalroleindeterminingwhoandhowaflyfights,andwhetheradominancerelationshipforms.“ourdataindicatethataggressivebehaviorsarehardwiredintothefly’snervoussystem”40/142alsovertebratese.g.zebrafishGahtan,E.,Tanger,P.,&Baier,H.(2023).Visualpreycaptureinlarvalzebrafishiscontrolledbyidentified(fourofthem)reticulospinalneuronsdownstreamofthetectum.JournalofNeuroscience,25(40),9294-9303.“Manyvertebratesareefficienthuntersandrecognizetheirpreybyinnateneuralmechanisms.Duringpreycapture,theinternalrepresentationoftheprey'slocationmustbeconstantlyupdatedandmadeavailabletopremotorneuronsthatconveytheinformationtospinalmotorcircuits.”“Seven-day-oldzebrafishorientedtoward,chased,andconsumedparameciawithhighaccuracy.”41/142Alsobirdse.g.Dilger(1961)42/142Alsoformammals Choietal.(2023)Lhx6delineatesapathwaymediatinginnatereproductivebehaviorsfromtheamygdalatothehypothalamus,Neuron,46(4),647-660(inembryonicandadultmice)“Virtuallyallmetazoanorganismsexhibitinnatereproductiveanddefensivebehaviorsthataretriggeredbysignalssensedfromconspecificsorpredators.….Thestereotypicalnatureofthesebehaviorssuggeststhattheirunderlyingneuralcircuitsarelikelytobegenetically‘hard-wired’.”“Inmammals,innatereproductiveanddefensivebehaviorsaremediatedbyanatomicallysegregatedconnectionsbetweentheamygdalaandhypothalamus.”43/142Slide4fromthe2023NobelLecture:LindaBuck44/14245/142Contraststhereremainverycontrastingpositionswithincontemporarypsychologyparticularlyrelatingtohowmuchemphasisisgiventobroadlybiologicalasopposedtopsychosocialevidenceandtheory.Thecontrastsarelessstarkifweuse“horsesforcourses”:explaininghowtheolfactorysystemworksinmiceisdifferentfromtheorisingaboutvotingintentionsintheUkraine(2023)ortheToryleadershipelection(2023)orpoliticaleventsinLebanon(2023)46/142EvolutionaryPsychologyAttemptstoexplainhumanpsychologyasaseriesofspecializedadaptationsDriveninpartbyChomskyanlinguistics(seelastweek’slectures):Pinkerhaswrittenseveralmoregeneralbooks,mostrecently“TheBlankSlate”(2023)aswellas“TheLanguageInstinct(1994)47/142AdaptationsWilliams(1966)definedanadaptationas“acharacteristicthathasarisenthroughandbeenshapedbynaturaland/orsexualselection.Itregularlydevelopsinmembersofthesamespeciesbecauseithelpedtosolveproblemsofsurvivalandreproductionintheevolutionaryancestryoftheorganism.Consequentlyitcanbeexpectedtohaveageneticbasisensuringthattheadaptationispassedthroughthegenerations”.48/142SpandrelsGouldandLewontin,1979;Gould,1997“AnadaptationistprogrammehasdominatedevolutionarythoughtinEnglandandtheUnitedStatesduringthepastfortyyears.Itisbasedonfaithinthepowerofnaturalselectionasanoptimizingagent.”Wefaulttheadaptationistprogrammeforitsunwillingnesstoconsideralternativestoadaptivestories……..”spandrelsandexaptationsaresideeffectsofnaturalselection49/142Evolutionarypsychology,originallyonthefringeofacademicpsychology..,hasgainedrespectabilitywithinthelastdecade.Articleswrittenfromanevolutionarypsychologicalperspectivearefoundinthefield’smostprestigiousoutlets;ithasprofessionalsocietiesandjournalsofitsown;collegecoursesandtextbooksaredevotedtoit;andthereareacademicpositionsspecificallydesignatedforevolutionarypsychologists.

Bjorklund,D.F.,&Smith,P.K.(2023).Evolutionarydevelopmentalpsychology:Introductiontothespecialissue.JournalofExperimentalChildPsychology,85(3),195-198EvolutionaryPsychology50/142ToobyandCosmidesCosmides,L.(1989).Thelogicofsocialexchange:hasnaturalselectionshapedhowhumansreason?StudieswiththeWasonselectiontask.Cognition,31:187-276.

Duchaine,B.,Cosmides,L.,&Tooby,J.(2023).Evolutionarypsychologyandthebrain.CurrentOpinioninNeurobiology,11(2),225-230.51/142SwissArmyKnifeCosmides:TheSwissArmyknifeisaflexibletool.Itsflexibilityisnottheresultofhavingjustonetoolthatisappliedtoallproblems.Instead,itisabundleoftools,eachwell-designedforsolvingadifferentproblem–.Similarly,thehumanminddoesnothavejustoneblunttoolforsolvingallproblems–andifitdid,wewouldbeverylimitedindeed..52/142Cosmides(1989)Logic:IfPthenQisonlyviolatedbyP&~QTypicallyparticipantsdonotusethislogicintheWason4cardtest(ifvowel,thenevennumberonback)A.ifyouhaveabuspass,thenyoutravelbybusB.ifyoutravelbybus,thenyouhaveabuspassCosmidesusedmanymoreelaboratescenarios,andfoundastrongbiastowards“detectingcheaters”inthatparticipantsgetAwrong,butBright.53/142Butthereiswidespreaddisagreement,bothwiththespecificclaimsmadeaboutreasoningandtheWasoncard-turningtest,Andwiththegeneralclaimsabouthighlyspecializedmentaltoolsforsolvingspecificproblems54/142ExamplesHowever,afewexamplesfollowofpapersfirmlyinthefieldofevolutionarypsychologyinrecentissuesofreputablejournals.Catatonia,AnorexiaNervosaanddepressionareproposedasadaptations,thereisafairlygeneraltheoryaboutindividualdecisionrulesinteractingwithgroupdynamics,apaperproposinganevolutionaryaccountofhumanfacialexpressionofpain,andapaperarguingthatahuman“innatereleasingmechanism”forunderstandingagencyisakeyfeatureofreligiousconceptsofthesupernatural.55/142Moskowitz,A.K.(2023).“Scaredstiff”:Catatoniaasanevolutionary-basedfearresponse.PsychologicalReview,111(4),984-1002.56/14257/142Guisinger,S.(2023).Adaptedtofleefamine:Addinganevolutionaryperspectiveonanorexianervosa.PsychologicalReview,110(4),745-761.Anorexianervosa(AN)is..attributedtopsychologicalconflicts,attemptstobefashionablyslender,neuroendocrinedysfunction,…….Considerableresearchrevealsthesetheoriestobeincomplete…..ThisarticlepresentsevidencethatAN'sdistinctivesymptomsofrestrictingfood,denialofstarvation,andhyperactivityarelikelytobeevolvedadaptivemechanismsthatfacilitatedancestralnomadic

foragersleavingdepletedenvironments;geneticallysusceptibleindividualswholosetoomuchweightmaytriggerthesearchaicadaptations.ThishypothesisaccountsfortheoccurrenceofAN-likesyndromesinbothhumansandanimalsandisconsistentwithchangesobservedinthephysiology,cognitions,andbehaviorofpatientswithAN.58/142Guisingertable59/142DepressionAllen,N.B.,&Badcock,P.B.T.(2023).Darwinianmodelsofdepression:Areviewofevolutionaryaccountsofmoodandmooddisorders.ProgressinNeuro-Psychopharmacology&BiologicalPsychiatry,30(5),815-826.Accordingtothesocialriskhypothesis,depressionrepresentsanadaptiveresponsetothethreatofexclusionfromsocialrelationshipsthat,overthecourseofevolution,havebeencriticaltomaintaininganindividual'sfitnessprospectsintheancestralenvironment,depressioninduced:(i)sensitivitytosocialrisk/threat;(ii)signalingbehavioursthatelicitsocialsupport;and(iii)areductioninriskybehaviours60/142Kenrick,D.T.,Li,N.P.,&Butner,J.(2023).Dynamicalevolutionarypsychology:Individualdecisionrulesandemergentsocialnorms.PsychologicalReview,110(1),3-28.Followingevolutionarymodels,psychologicalmechanismsareconceivedasconditionaldecisionrulesdesignedtoaddressfundamentalproblemsconfrontedbyhumanancestors,Anewtheoryintegratingevolutionaryanddynamicalapproachesisproposed.Threeseriesofsimulationsexaminingtrade-offsincooperationandmatingdecisionsillustratehowindividualdecisionmechanismsandgroupdynamicsmutuallyconstrainoneanother,andofferinsightsaboutgene-cultureinteractions.61/142KenrickandButner,2023“Atthemostgenerallevel,evolutionarypsychologycanbedefinedasthestudyofcognitive,affective,andbehavioralmechanismsasthesolutionstorecurrentadaptiveproblems.”“Alongwiththemorphologicalfeaturesdesignedbynaturalselection,organismsalsoinheritcentralnervoussystems……Thebehaviouralinclinationsofabatwouldnotworkwellinthebodyofadolphinorgiraffeandvice-versa.”62/14263/142KenrickandButtnerwrong

overaperiodof35yearsinSweden(1965-1999),therewasnooverallover-representationofstepchildrenasvictims.Temrin,Nordlund,&Sterner,H.(2023)Infamilieswithbothstepchildrenandchildrengeneticallyrelatedtotheoffender,geneticchildrentendedtobemorelikelytobevictims.64/142Williams,A.C.D.(2023).Facialexpressionofpain:Anevolutionaryaccount.BehavioralandBrainSciences,25(4),439-+.Thispaperproposesthathumanexpressionofpain..,,arisesfromevolvedpropensities.Thefunctionofpainistodemandattentionandprioritiseescape,recovery,andhealing;whereotherscanhelp…,adistinctandspecificfacialexpressionofpainfrominfancytooldage,consistentacrossstimuli,andrecognizableaspainbyobservers.……..therehasbeenskepticismaboutthepresenceorextentofpain,judgmentsofmalingering,andsometimesthewithholdingofcaregivingandhelp.…anevolutionaryaccountcangenerateimprovedassessmentofpainandreactionstoit.65/142Darwin’s“Theexpressionoftheemotionsinmanandanimals”(1872)66/142Pelegetal.(2023).Hereditaryfamilysignatureoffacialexpression.PNAS103(43),15921-15926

Correlatedfacialexpressionsincongenitallyblindsubjectsandtheirseeingrelatives,anticipatesgenes.67/142FurtherexamplesRhodes,G.(2023).Theevolutionarypsychologyoffacialbeauty.AnnualReviewofPsychology,57,199-226.facepreferencesmaybeadaptationsformatechoicebecauseattractivetraitssignalimportantaspectsofmatequality,suchashealthAverageness,symmetry,andsexualdimorphismaregoodcandidatesforbiologicallybasedstandardsofbeauty68/142Atran,S.,&Norenzayan,A.(2023).Religion'sevolutionarylandscape:Counterintuition,commitment,compassion,communion.BehavioralandBrainSciences,27(06),713-730.

Religionisnotanevolutionaryadaptationperse,butarecurringculturalby-productofthecomplexevolutionarylandscapeAkeyfeatureofthesupernaturalagentconceptscommontoallreligionsisthetriggeringofan“InnateReleasingMechanism,”or“agencydetector,”whoseproper(naturallyselected)domainencompassesobjectsrelevanttohominidsurvival–suchaspredators,–butwhichactuallyextendstomovingdotsoncomputerscreens,voicesinwind,andfacesonclouds.69/142DomainGeneralandDomainSpecificThe“Swissarmyknife”ideaismoreformallyexpressedintermsofdomainspecificormodularcapacities.Thenextpaperarguesthatgeneralintelligenceisalsodomain-specificThisisdangerousforEvolutionaryPsychology,sinceitopensthedoortotheideathathumanevolutionendedupbyprovidinguswithveryopen-endedandgeneralpurposepsychologicalcapacities.70/142Kanazawa,S.(2023).Generalintelligenceasadomain-specificadaptation.PsychologicalReview,111(2),512-523Generalintelligence(g)posesaproblemforevolutionarypsychology'smodularviewofthehumanbrain.Theauthor….arguesthatgeneralintelligenceevolvedasadomain-specificadaptationfortheoriginallylimitedsphereofevolutionarynoveltyintheancestralenvironment…Ithasaccidentallybecomeuniversallyimportantmerelybecausewenowliveinanevolutionarilynovelworld71/142Kanisawa,PsychReview202372/142MoreDomainGeneralideasAtkinson,A.P.,&Wheeler,M.(2023).Thegrainofdomains:Theevolutionary-psychologicalcaseagainstdomain-generalcognition.Mind&Language,19(2),147-176. ..evolutionarypsychologistshavearguedthatourinnatepsychologicalendowmentconsistsofnumerousdomain-specificcognitiveresources,ratherthanafewdomain-generalones.… Weconclude(a)thatthefundamentallogicofDarwinism,…..doesnotentailthattheinnatemindconsistsexclusively,orevenmassively,ofdomain-specificfeatures,and(b)thatamixedinnatecognitiveeconomyofdomain-specificanddomain-generalresourcesremainsagenuineconceptualpossibility.73/142HumanAncestors “psychologicalmechanismsareconceivedasconditionaldecisionrulesdesignedtoaddressfundamentalproblemsconfrontedbyhumanancestors”(KenrickandButner,2023)Thisisatypicalclaiminevolutionarypsychology,butthereseemslittledetailedinterestinwhathumanancestorsmighthavedone.74/142HumanEvolutionTheepistemologyofhumanevolutionisnecessarilydifficult,sinceitreliesonfossils,butfossilevidencehasareasonabletrackrecordinotherareas,andhumanartefacts,inparticularstonetools,provideanothersourceofevidence75/142Humanevolution,summarisedonp.6ofhandout76/142Millionstop77/142FamilyTree78/142Anewearlyfossil(2023)79/142Alemseged,Z.,etal.(2023).AjuvenileearlyhomininskeletonfromDikika,Ethiopia.Nature,443(7109),296-301Dikikaisonly4kmfromwhere‘Lucy’wasfound(Australopithecusafarensis)TheDikikaspecimen,from3.3myrsagowasabout3yrsoldandprobablyfemale.Thelegswerehuman-likeforbi-pedalwalking,butthearmsandhandsape-like.Thehyoidbone(forthelarynx)wasalsoape-like80/142NewNeanderthaldata:Greenetal.,(2023)Suggestscommonancestor~450,000yrsago81/142HumanuniquenessThehumanbrainisuniquelylargeItisalsofunctionallylateralizedinawaywhichdiffersfromchimpanzeesItmaybemetabolicallyenhancedCacaresetal(2023)Itmayincludedifferentphysiologicalcomponents(Allmanetal.,2023)Itmaybeorganizeduniquely,e.g.largefrontallobes(Deacon,1997)82/142Numberofneuronsinthenervoussystem1,000,000,000,000350,000,000,000100,000,000,000500,000,000300,000,00050,000,000850,000250,00020,000381302Homosapiens(maybe1014)ChimpanzeeRhesusmonkeyMouseOctopusSticklebackHoneybeeFruitflySeaslugThreadwormmaleThreadworm83/14284/14285/142InStriedter,G.F.(2023).PrecisofPrinciplesofbrainevolution.Striedterbrainszie86/142Dorus,S.,etal.(2023).AcceleratedevolutionofnervoussystemgenesintheoriginofHomosapiens.Cell,119(7),1027-104087/142Human,chimp,organg,Rhesus88/142primarymicrocephaly89/142PontingandJackson,2023…….recentadvancesfromthecloningoftwohumandiseasegenespromisetomakeinroadsinthearea..ofbrainsizeevolution.Microcephalin(MCPH1)andAbnormalspindle-likemicrocephalyassociated(ASPM)aregenesmutatedinprimarymicrocephaly.Inthis,thebrainisofasizecomparablewiththatofearlyhominids.Ithasbeenproposedthatthesegenesevolvedadaptivelywithincreasingprimatebrainsize.….bothgeneshaveundergonepositiveselectionduringgreatapeevolution.theevolutionarypatternsofallfourpresentlyknownprimarymicrocephalygenesareconsistentwiththehypothesisthatgenesregulatingbrainsizeduringdevelopmentmightalsoplayaroleinbrainevolutioninprimatesandespeciallyhumans(Evans,2023)90/142MoreonbrainsizegenesEvansetal.,(2023)claimthemicrocephalinhascontinuedtoevolveadaptivelyinmodernhumansTheysayonegeneticvariantofmicrocephalinappearedasrecentlyas37,000yearsago.Thesameteam(Merkel-Bobrovetal,2023)saythatAPSM,anothergeneregulatingbrainsize,hadanewvariantonly5,800yearsago91/142Huxley’scomparisons“Sofarascerebralstructuregoestherefore,itisclearthatmandifferslessfromtheChimpanzeeortheOrang,thanthesedoevenfromthemonkeys,andthatthedifferencebetweenthebrainsoftheChimpanzeeandofManisalmostinsignificant,whencomparedwiththatbetweentheChimpanzeebrainandthatofaLemur.“(Darwin,1874/1901,p.312)92/142semendeferi193/142TheSemendeferietal.,(2023)tableSemendeferitable94/142Schoenemannetal.(2023)recentlysuggestedthatprefrontalwhitematterisdisproportionatelylargerinhumansthaninotherprimates

butSherwoodetal.(2023)counteredthata)theboundarybetweenprefrontalandothercortexisnotwelldefined;andb)thatinanycase,althoughthedatashowedhumanshavingmorewhitematterthantheaverageprimate,theydidnotshowadifferencebetweenhumansandgreatapes.Brainre-organization:expansionofthefrontallobesThesherwood202395/142Allmanetal2023VonEconomoneurons(VENs)arearecentlyevolvedcelltypewhichmaybeinvolvedinthefastintuitiveassessmentofcomplexsituations.Assuch,theycouldbepartofthecircuitrysupportinghumansocialnetworks.WeproposethattheVENsrelayanoutputoffronto-insularandanteriorcingulatecortextothepartsoffrontalandtemporalcortexassociatedwiththeory-of-mindWeproposethatinautismspectrumdisorderstheVENsfailtodevelopnormally96/142Allmanetal.,202397/142Hutsler,20237autopsies:50-97yrsofage.NochimpanzeesHumanBrainAsymmetries98/142Sun,T.,&Walsh,C.A.(2023).Molecularapproachestobrainasymmetryandhandedness.NatureReviewsNeuroscience,7(8),655-66299/142Sun,T.,&Walsh,C.A.(2023).Molecularapproachestobrainasymmetryandhandedness.100/142Elevatedneuronalactivity?Caceresetal.(2023)appliedavarietyofgenetictechniquesto