Hari imyumvire imaze imyaka myinshi ikwirakwizwa ivuga ko abagore bavuga amagambo menshi cyane kurusha abagabo, bamwe bakemeza ko ku munsi umugore ashobora kuvuga amagambo 20,000 mu gihe umugabo atarenza 7,000. Ibi bivuze ikinyuranyo cy’amagambo asaga ibihumbi 13 ku munsi. Ariko se koko ibi bifite ishingiro ry’ubushakashatsi, cyangwa ni imyumvire yakwirakwijwe n’ibitangazamakuru gusa?
Abashakashatsi bamwe bemeza ko iri tandukaniro rishingiye ku miterere y’ubwonko n’uburyo abantu b’igitsina runaka bagira imyumvire y’itumanaho. Bavuga ko abagore muri rusange ubusanzwe bagira bwo kugaragaza amarangamutima no gusabana kurusha abagabo, bigatuma bagaragara nk’abavuga amagambo menshi mu buzima bwa buri munsi.
Nyamara ubushakashatsi bwinshi bwimbitse bugaragaza ko iryo tandukaniro rifatwa nk’ukuri rifite ishingiro rito cyane. Ubusesenguzi bwakozwe ku bushakashatsi 73 bwari bwarakorewe ku bana bwabonye ko abakobwa bavugaga amagambo menshi kurusha abahungu, ariko iryo tandukaniro ryari rito cyane kandi rikagaragara gusa mu biganiro bagiranaga n’ababyeyi babo, ntiriboneke mu biganiro bari kugirana n’inshuti zabo. Ibi byagaragaye kugeza ku myaka ibiri n’igice gusa, bikaba bishobora kugaragaza uburyo abakobwa n’abahungu batangira kuvuga mu bihe bitandukanye aho kuba ari imiterere idasanzwe y’igitsina.
Ku rwego rw’abantu bakuru, ubushakashatsi bwa Campbell Leaper, umushakashatsi wo muri University of California, Santa Cruz, bwerekanye ko mu bihe bimwe abagabo aribo bavugaga amagambo menshi, nubwo iryo tandukaniro ryari rito. Ubu bushakashatsi bwasanze kandi ko ibisubizo byavaga mu igeragezwa ryakorwaga muri laboratwari byari bitandukanye cyane n’ibyavaga mu buzima busanzwe. Ibi byerekana ko abagabo bashobora kugaragara nk’abavuga menshi iyo bari mu bihe bidasanzwe, mu gihe mu buzima busanzwe nta tandukaniro rigaragara cyane.
Ibi byashimangiwe kandi n’ubusesenguzi bwa Deborah James na Janice Drakich mu 1993, aho mu bushakashatsi 56 bwarebwe, 34 muri bwo bwari bwarasanze abagabo bavuga amagambo menshi kurusha abagore mu bihe bimwe na bimwe, mu gihe bubiri gusa aribwo bwagaragaje ko abagore bavugaga amagambo menshi kurusha abagabo.
Ubushakashatsi bw’umuhanga mu by’imitekerereze James Pennebaker wo muri University of Texas, Austin, bwasohotse mu kinyamakuru Science mu 2007, bwifashishije ikoranabuhanga ryo gufata amajwi mu buryo bw’igereranya mu buzima busanzwe. Bwagaragaje ko mu masaha 17 ku munsi, abagore bo muri Amerika na Mexique bavugaga amagambo 16,215, mu gihe abagabo bavugaga 15,669. Urebye iyi mibare, ntiharimo itandukaniro rikomeye.
Ubundi bushakashatsi bwerekanye ko itandukaniro rishobora gushingira ku ruhare rw’uwumva cyangwa urwego rw’ibiganiro. Urugero, Janet Holmes wo muri Victoria University of Wellington yakoreye ubushakashatsi ku nama za rubanda ijana, asanga abagabo aribo babazaga ibibazo byinshi kurusha abagore, kandi bagira ijambo ryinshi mu ruhame nubwo umubare wabo hari ubwo wari mucye.
Iyi myumvire ivuga ko abagore bavuga amagambo menshi cyane kurusha abagabo yakwirakwijwe cyane n’igitabo ’The Female Brain’ cyanditswe na Louann Brizendine mu 2006, aho byavugwaga ko umugore avugaga amagambo 20,000 ku munsi naho umugabo akavuga 7,000. Nyuma, ubwo Prof. Mark Liebermann wo muri University of Pennsylvania yasuzumaga ayo makuru, yasanze nta shingiro afite, ndetse umwanditsi yemera kuyakuramo mu bitabo bizakurikiraho.
Ibi byose bigaragaza ko nubwo imyumvire isanzwe ikomeje gushyigikira ko abagore bavuga amagambo menshi kurusha abagabo, ubushakashatsi bwimbitse bwerekana ko nta tandukaniro rikomeye riri hagati y’ibitsina byombi. Ahubwo, uburyo umuntu avuga amagambo menshi cyangwa make biterwa n’umuco, ibihe arimo, amarangamutima ndetse n’icyo ibiganiro bishingiyeho, aho gushingira ku gitsina runaka.
