Nyob rau hauv lub 60s, thawj ethological kev tshawb fawb ntawm cov me nyuam tus cwj pwm tau ua. Ntau qhov haujlwm tseem ceeb hauv cheeb tsam no tau ua tiav ib txhij los ntawm N. Blairton Jones, P. Smith thiab C. Connolly, W. McGrew. Thawj tus tau piav qhia txog ntau yam kev coj ua, kev txhoj puab heev thiab kev tiv thaiv hauv cov menyuam yaus thiab tau hais tawm goo play raws li kev ywj pheej ntawm tus cwj pwm [Blurton Jones, 1972]. Cov tom kawg tau ua cov kev soj ntsuam ntxaws ntxaws ntawm tus cwj pwm ntawm cov menyuam yaus hnub nyoog txij li ob xyoos cuaj hli mus rau plaub xyoos cuaj lub hlis tom tsev thiab hauv tsev kawm qib kindergarten (hauv cov tuam txhab ntawm niam txiv thiab tsis muaj lawv) thiab pom tias muaj kev sib txawv ntawm poj niam txiv neej hauv kev coj noj coj ua. Lawv kuj tau hais tias qhov sib txawv ntawm tus kheej tuaj yeem piav qhia los ntawm cov ntaub ntawv ntawm kev coj tus cwj pwm sab nraud [Smith, Connolly, 1972]. W. McGrew hauv nws phau ntawv "The Ethological Study of Children's Behavior" tau muab cov ncauj lus ntxaws ntxaws ntawm cov menyuam yaus tus cwj pwm thiab ua pov thawj qhov kev siv ntawm cov tswv yim thiab cov tswv yim, xws li kev tswj hwm, thaj chaw, kev cuam tshuam ntawm pawg neeg ceev ntawm kev coj cwj pwm, thiab cov qauv ntawm saib [McGrew, 1972]. Ua ntej no, cov ntsiab lus no tau suav hais tias siv tau rau cov tsiaj txhu thiab tau siv dav los ntawm cov kws kho mob primatologists. Kev txheeb xyuas kev ncaj ncees ntawm kev sib tw thiab kev tswj hwm ntawm cov menyuam kawm ntawv preschool ua rau nws tuaj yeem txiav txim siab tias kev tswj hwm hierarchy hauv cov pab pawg no ua raws li cov cai ntawm kev hloov pauv, nws tau tsim sai sai thaum lub sijhawm tsim cov pab pawg sib raug zoo thiab nyob ruaj khov nyob rau lub sijhawm. Tau kawg, qhov teeb meem nyob deb ntawm kev daws teeb meem tag nrho, vim tias cov ntaub ntawv ntawm cov kws sau ntawv sib txawv taw qhia qhov sib txawv ntawm qhov tshwm sim no. Raws li ib qho kev pom, kev tswj hwm ncaj qha cuam tshuam nrog kev nyiam nkag mus rau cov peev txheej tsawg [Strayer, Strayer, 1976; Charlesworth thiab Lafreniere 1983]. Raws li lwm tus - nrog rau kev muaj peev xwm nrog cov phooj ywg thiab teeb tsa kev sib raug zoo, nyiam mloog (peb cov ntaub ntawv ntawm cov menyuam yaus Lavxias thiab Kalmyk).
Ib qho chaw tseem ceeb hauv kev ua haujlwm ntawm cov menyuam yaus txoj kev coj ncaj ncees tau nyob los ntawm kev kawm ntawm kev sib txuas lus tsis hais lus. Kev siv lub ntsej muag lub ntsej muag coding system tsim los ntawm P. Ekman thiab W. Friesen tau tso cai rau G. Oster los tsim kom cov menyuam mos tuaj yeem ua txhua yam kev ua kom cov leeg nqaij zoo li cov neeg laus [Oster, 1978]. Kev soj ntsuam ntawm lub ntsej muag ntawm cov menyuam yaus pom thiab qhov muag tsis pom nyob rau hauv lub ntsiab lus ntawm kev ua haujlwm nruab hnub [Eibl-Eibesfeldt, 1973] thiab cov kev cuam tshuam ntawm cov menyuam yaus hauv cov xwm txheej sim [Charlesworth, 1970] coj mus rau qhov xaus tias cov menyuam dig muag tsis muaj peev xwm ua tau. kev kawm pom kev ua kom pom lub ntsej muag zoo sib xws hauv cov xwm txheej zoo ib yam. Kev soj ntsuam ntawm cov menyuam yaus hnub nyoog ob mus rau tsib xyoos tau ua rau nws muaj peev xwm tham txog kev nthuav dav ntawm cov lus qhia dav dav ntawm cov kab lus sib txawv [Abramovitch, Marvin, 1975]. Raws li menyuam yaus txoj kev muaj peev xwm hauv zej zog loj hlob tuaj, nruab nrab ntawm cov hnub nyoog ntawm 2,5 thiab 4,5 xyoo, kuj tseem muaj qhov nce ntawm kev siv lub ntsej muag luag ntxhi [Cheyne, 1976]. Kev siv cov txheej txheem kev coj noj coj ua hauv kev txheeb xyuas cov txheej txheem kev loj hlob tau lees paub tias muaj lub hauv paus innate rau kev loj hlob ntawm tib neeg lub ntsej muag [Hiatt et al, 1979]. C. Tinbergen tau siv cov txheej txheem kev coj noj coj ua hauv kev puas siab ntsws rau menyuam yaus los tshuaj xyuas qhov tshwm sim ntawm kev puas siab puas ntsws hauv cov menyuam yaus, ua rau pom qhov tseeb tias tsis txhob ntsia, ib yam rau cov me nyuam autistic, yog tshwm sim los ntawm kev ntshai ntawm kev sib cuag.