Ubushakashatsi buherutse gukorwa n’abahanga bo muri Kaminuza ya Texas, mu kigo cyayo cyitwa University of Texas Health Science Center, bwerekanye ko abantu basinzira amasaha menshi cyane cyane cyane abamara amasaha icyenda cyangwa arenga ku ijoro rimwe bafite ibyago byinshi byo gusaza kw’ubwonko hakiri kare, ndetse no gutakaza ubushobozi bwo kwibuka no gutekereza neza.
Ubu bushakashatsi bwakorewe ku bantu 1853 bafite imyaka iri hagati ya 27 na 85, bwagaragaje ko gusinzira birengeje urugero bishobora kugabanya imbaraga z’ubwonko, ku buryo ubwonko bw’umuntu bugaragaza ibimenyetso byo gusaza mbere y’imyaka itandatu n’igice ugereranyije n’undi muntu usinzira mu rugero rusanzwe.
Abakozweho ubushakashatsi basuzumwaga buri myaka ine. Ibi byabaga biherekejwe no kubazwa ku masaha bamara baryamye buri joro, ndetse hakarebwa n’imikorere y’ubwonko bwabo mu bijyanye n’ubushobozi bwo kwibuka, gufata ibyemezo mu buryo buboneye, no gutekereza byimbitse.
Abantu basanzwe baryama amasaha icyenda cyangwa arenga buri joro mu gihe cy’imyaka 20, bagaragaje impinduka zigaragara ku mikorere y’ubwonko ugereranyije n’abaryamaga amasaha make cyangwa agenewe umuntu mukuru (ari hagati ya 7 na 8). Izo mpinduka harimo gusaza kw’ubwonko kutari kwitezwe ku myaka yabo, kugabanuka kw’ubushobozi bwo gufata ibyemezo, n’ikibazo cyo kwibuka amakuru.
Byagaragaye kandi ko abantu bafite ibibazo by’ubuzima bwo mu mutwe (nk’agahinda gakabije, ihungabana, n’ibindi) ari bo bashobora kuba bashobora kuryama amasaha menshi kurushaho. Ariko n’abatari bafite ibibazo by’umutwe basanzwe, hari abagaragaje ingaruka mbi zo gusinzira igihe kirekire.
Aba bashakashatsi basanze ko gusinzira amasaha menshi atari byiza nk’uko benshi babitekereza, cyane cyane iyo bibaye umuco w’igihe kirekire. Basabye abantu gushyira ingufu mu kugira uburyo bwo kuryama bwiza kandi burimo umurongo, aho umuntu aryama igihe gihagije ariko atarengereye ku buryo bihinduka ikibazo cy’ubuzima bw’ubwonko.
Nubwo gusinzira bifite akamaro gakomeye ku buzima, ubushakashatsi bugaragaza ko igihe kirenze urugero bishobora kwangiza ubwonko aho kubugirira akamaro. Gufata amasaha 7–8 yo kuryama buri joro ni cyo kigero cyiza cyafasha ubwonko gukomeza gukora neza no kwirinda gusaza hakiri kare.
