Waists, Hips da Sexy Hourglass Siffar

Karatu da yawa - galibi ga mata kuma da wuya ga maza - sun yi ƙoƙarin gano sifofin jikin da ƙimar jinsi ke da daɗi. Manufar gama gari ita ce gano takamaiman fasalulluka waɗanda wataƙila sun samo asali azaman siginar da ke nuna yuwuwar haifuwar mata. Amma shin irin waɗannan alamomi masu sauƙi za su iya zama maɓallan tsarin rikitarwa na zaɓin abokin tarayya?

Alamar shari’a

Ina tunawa da darussan ɗabi'a ta tsohon mai ba ni shawara Niko Tinbergen shekaru hamsin da suka gabata. Musamman abin burgewa shine bincikensa na farko a cikin neman aure a cikin kifi mai kaskantar da kai, ƙwallon kafa uku. Yayin da lokacin kiwo ke farawa, babban namiji ya kafa yanki a cikin ruwa mai zurfi kuma ya gina gida mai kama da rami tare da tarkacen ciyayi a kan ƙaramin rami. Ga duk macen da ke wucewa da kumburin ciki, yana yin rawar zig-zag, da farko ya yi mata iyo sannan ya jagorance ta zuwa gida. Mace tana iyo ta cikin ramin, tana ɗora ƙwai, namiji kuma yana bi don takin. Bayan haka, yana shayar da ruwa ta cikin gida a kowane lokaci don ƙosar da ƙwai.

Wannan jerin tsararrakin ya jagoranci Tinbergen don gane alamar alamar - siginar mai sauƙi da ke fitar da takamaiman amsa. Rikicewar maza a cikin yankin kiwo yana haɓaka launin ja mai haske a ƙirjinsa, wanda duka yana jan hankalin mata kuma yana haifar da tashin hankali daga wasu maza. Hakazalika, ciki mai ɗauke da kwai na mace alama ce ta motsawa da neman aure. Ta yin amfani da muggan dabaru da ke kwaikwayon mahimman abubuwa kawai, Tinbergen ya nuna cewa ja-ja-ja-ja-ja-gora “namiji”, yana tafiya cikin yanayin zig-zag, yana jan hankalin mace zuwa gida, yayin da “mace” mai kumburin ciki ta haifar da zawarcin namiji. Lallai, Tinbergen ya nuna cewa siginar da ta wuce kima - babban abin ƙarfafawa - na iya zama mafi inganci. Misali, “namiji” mai dumbin yawa tare da nonon ja mai haske fiye da na al'ada ya haifar da tashin hankali daga maza masu gwaji.

Saki sigina a cikin mata?

Kodayake halayen ɗan adam ya fi rikitarwa, masu bincike sun nemi sigina iri ɗaya a cikin mata. A cikin daidaitattun batutuwa na gwaji ana tambayar su don ƙimar kyawun hotuna masu girma biyu. Bayan takardu guda biyu na Devendra Singh a 1993, hankali ya maida hankali kan rabon tsakanin kugu da faɗin kwatangwalo a cikin tsarin jikin mace, yana nuna rarraba kitse na jiki. Waist: rabon kwatangwalo (WHRs) da kyar ya daidaita tsakanin jinsi. Hanyoyin lafiya na al'ada sune 0.67-0.80 ga matan da suka fara haihuwa da 0.85-0.95 ga maza. Ganin cewa “duk ka’idojin zaɓin abokiyar ɗan adam dangane da ƙa’idojin juyin halitta suna ɗauka cewa kyawu yana ba da tabbaci ga ƙimar haihuwar mace .........”, binciken farko na Singh ya nuna cewa maza gabaɗaya suna ƙididdige adadin mata da ƙarancin WHR a kusa. 0.7 a matsayin mafi kyawu fiye da kowane tare da ƙimar girma.

An fassara matsanancin ƙari na sifar agogon agogo a cikin sanannen ƙarni na 19 na '' tsutsa-kugu '' corsets a matsayin babban abin ƙarfafawa wanda ke haɓaka kyawun mace. Abin ban mamaki, duk da haka, an fassara fasali na “Venus” daga Palaeolithic - tare da ragin WHR kusan 1.3 - an fassara su ta irin wannan hanyar.

Karatuttukan da suka biyo baya sun tabbatar da gaba ɗaya cewa maza gaba ɗaya suna kimanta sifofin jikin mata tare da WHR tsakanin 0.6 zuwa 0.8 a matsayin mafi kyawu. Bugu da ƙari, fifiko ga ƙarancin WHR ya kasance daidai a tsakanin yawancin al'adu da al'adu daban -daban. Cikin Babban Jima'i , Bayanan Alan Dixson sun fi son ƙimar WHR na 0.6 ga ɗaliban jami'ar China da Hadza mafarautan Tanzania, 0.7 ga Indiyawa da Baƙin Amurkawa, da 0.8 ga maza a Bakossiland, Kamaru. A cikin takarda ta 2010, Barnaby Dixson da abokan aiki sun yi amfani da sa ido don tantance fifikon maza don WHR na mata da girman nono. Sun yi rikodin gyarawa na farko da lokutan zama don maza suna kallon hotunan gaban mace guda da aka yi amfani da su don bambanta a cikin WHR (0.7 ko 0.9) da girman nono. A cikin milliseconds 200 na farkon kowane gwaji, ko dai nono ko kugu ya haifar da gyaran gani na farko. Hotunan da ke da WHR na 0.7 an ƙidaya su a matsayin mafi kyawu, komai girman nono.

A cikin sadarwar 1998, duk da haka, Douglas Yu da Glenn Shepard sun ba da rahoton cewa fifikon maza ga mata masu ƙarancin WHR na iya zama ba al'adar duniya ba. Ganin cewa "duk al'adun da aka gwada zuwa yanzu an fallasa su ga tasirin rikice -rikicen kafofin watsa labarai na yamma", waɗannan marubutan sun tantance abubuwan da ake so a cikin al'umman da ke keɓe musamman na mutanen Matsigenka 'yan asalin kudu maso gabashin Peru. Mazan Matsigenka sun gwammace sharuɗɗa tare da babban WHR, suna kwatanta wannan kusan sifar tubular a matsayin mafi koshin lafiya. A cikin gwaje -gwajen wasu ƙauyuka akan ɗan ƙaramin ƙaruwa na yamma, fifikon WHR ya ci gaba da tuntuɓar waɗanda aka ruwaito don ƙasashen yamma. Yu da Shepard sun kammala da cewa gwaje -gwajen da suka gabata "wataƙila sun nuna yaɗuwar kafofin watsa labarai na yamma". Amma wannan binciken yana da matsala saboda an nemi maza su kimanta zane -zanen yamma daga karatun Singh na asali maimakon adadi mafi dacewa da al'adu.

WHR a gaban yawan jiki?

Matsalar ilimin kididdiga na rikice -rikice masu rikitarwa shima lamari ne (duba post na Yuli 12, 2013 Tarkon Stork-da-Baby ). Wasu dalilai na iya lissafa ƙungiyoyi tsakanin ƙarancin WHR da ƙimar kyan gani. Misali, an ba da shawarar cewa tasirin tuƙi na ainihi shine ma'aunin ma'aunin jiki (BMI).

A cikin 2011, Ian Holliday da abokan aiki sun yi amfani da bincike iri-iri na jikin mace don gina hotuna 3 masu girma-girma na kwamfuta waɗanda suka bambanta gwargwadon BMI ko WHR. An ba da rahoton ƙimar jan hankali tsakanin jinsi biyu da bambance -bambancen BMI amma ba a cikin WHR ba. Binciken kwakwalwa da aka yi rikodin tare da MRI mai aiki yayin gwaji ya nuna cewa canza ayyukan BMI da aka canza a ɓangarorin tsarin lada na kwakwalwa. An kammala cewa yawan jiki, ba siffar jiki ba, a zahiri yana jan hankali.

Duk da haka a cikin 2010, binciken al'adu tsakanin Devendra Singh, Barnaby Dixson, Alan Dixson da sauransu sun ba da sakamako daban. Waɗannan marubutan sun ba da izinin yuwuwar tasirin BMI ta amfani da hotunan gwaji na matan da suka yi aikin tiyata na micrograft don ƙuntata kugu da sake fasalin gindi, canza WHR kai tsaye. A cikin duk al'adun da aka gwada, maza sun yanke hukunci ga mata masu ƙarancin WHR a matsayin mafi kyawu ba tare da la'akari ko ƙaruwa a cikin BMI ba.

Wasu dalilai na taka tsantsan

Fassarar kowane mai nuna alama mai sauƙi na jan hankalin mata kamar WHR abin tambaya ne. Rudimentary 2D wakilcin jikin mace da aka saba amfani da shi a cikin gwaje -gwajen an cika su sosai idan aka kwatanta da haƙiƙanin haƙiƙanin 3D. Haka kuma, galibin abubuwan jikin mutum ana nuna su a kallon gaba. Ba a san kaɗan ba game da martanin maza ga ra’ayoyin baya ko gefe, balle ga gaskiyar 3D gaba ɗaya.

A cikin takarda ta 2009, James Rilling da abokan aiki sun yi amfani da ƙarin tsarin gwaji wanda ya ƙunshi bidiyon 3D da har yanzu 2D harbi na ainihin ƙirar mata suna jujjuyawa a sararin samaniya. Bincike ya nuna cewa zurfin ciki da da'irar kugu sune mafi tsinkayen abubuwan jan hankali, sama da WHR da BMI.

Candidateaya daga cikin manyan 'yan takara don siginar gaba - ɓarkewar gashin balaga wanda ke tasowa lokacin balaga kuma yana nuna sauyi zuwa mace - da wuya a yi la'akari. Babban abin ban mamaki shine binciken Christopher Burris da Armand Munteanu na ɗaliban karatun digiri na baya -bayan nan waɗanda, a tsakanin sauran abubuwa, sun tantance martanin da ke nuna bambancin launin fata a gashin gashin mata. Abin ban mamaki, an ƙaddara cikakkiyar rashin gashin gashi a matsayin mafi tayar da hankali gaba ɗaya. An fassara wannan tare da hasashe mai rikitarwa wanda ke haɗa gashin gashin balaguro a cikin mata zuwa matakan testosterone da rashin haihuwa da kuma danganta ƙimantawa mafi girma ga maza waɗanda suka fi dacewa da rashin haihuwa ga mace. Amma wani abu mai mahimmanci, mai tayar da hankali ya wuce wanda ba a ambata ba: A cikin kowane yanayin juyin halitta na ainihi, lallai rashin gashin balaga tabbas yana nuna rashin haihuwa saboda rashin balaga. Ta yaya mutum zai iya bayyana shaharar bikini na Brazil da ke kaɗawa cikin sharuddan juyin halitta?

Ko da cikakken bayani, ya kamata mu yi taka tsantsan da duk wani bayanin juyin halitta wanda ke rage hadaddun mu'amalar ɗan adam zuwa sauƙi mai sauƙaƙawa-amsa halayyar sandarka.

Nassoshi

Burris, C.T. & Munteanu, A.R. (2015) Babban tashin hankali don mayar da martani ga gashin gashin balaguro na mace yana da alaƙa da mafi kyawun halayen halayen rashin haihuwa tsakanin mata tsakanin maza da mata. Jaridar Kanada ta Jima'i24 : DOI: 10.3138/cjhs.2783.

Dixson, AF (2012) Jima'i Mai Girma: Nazarin Kwatancen Prosimians, Birai, Biri da Halittar Dan Adam (Buga na Biyu). Oxford: Jami'ar Jami'ar Oxford.

Dixson, BJ, Grimshaw, G.M., Linklater, WL & Dixson, AF (2010) Sa ido-ido na abubuwan da maza ke so don girman kugu-da-hip da girman nono na mata. Taskar Halin Jima'i40 :43-50.

Holliday, IE, Longe, OA, Thai, N., Hancock, PB & Tovée, M.J.(2011) BMI ba WHR yana daidaita martanin BOLD fMRI a cikin hanyar sadarwar lada ta sub-cortical lokacin da mahalarta ke yin hukunci akan kyawun jikin mace. KYAUTA Daya6(11) Saukewa: E27255.

Rilling, JK, Kaufman, TL, Smith, EO, Patel, R. & Worthman, CM (2009) Zurfin ciki da da'irar kugu a matsayin masu ƙaddara tasirin ƙimar mace. Juyin Halitta da Halayen Dan Adam30 :21-31.

Singh, D. (1993) Mahimmancin daidaitawa na jan hankalin mata: rawar kugu zuwa rabo hip. Jaridar Mutum da Ilimin Zamantakewa65 :293-307.

Singh, D. (1993) Siffar jiki da jan hankalin mata: muhimmiyar rawa na rabo-zuwa-hip. Yanayin Dan Adam4 :297-321.

Singh, D., Dixson, BJ, Jessop, TS, Morgan, B. & Dixson, AF (2010) Ƙetare yarjejeniya ta al'adu don raɗaɗin kugu da kwatangwalo na mata. Juyin Halitta da Halayen Dan Adam31 :176-181.

Tinbergen, N. (1951) Nazarin Ilhami. Oxford: Clarendon Danna.

Yau, D.W. & Shepard, GH (1998) Shin kyawu yana cikin idon mai kallo? Yanayi396 :321-322.