III. CAC Y£U T6 ANH HlfCJNG D^ NHANH VI GAY HAN < 1)
d nhung iia tre co tuoi tho bi nguoc ai (Casp iv & c6ng su, 2002; Moffitt va eng
sir, 2003). Khdng phai chi nhirng “gen x£u” hay nhung mdi trudng x&i mod dan
den gay hah hoSc chd'
ng ddixa hdi.Dung hon la gen da lam cho motsd'
duratretrd
ndnnhaycam han va phan ting laimanh hon vdisungugcdai.
Nam 2005,hern2.500 nguditrudngthanh tai Mitham giamdtkhao sdt v6 sure
khoe do nhk tdi pham hoc Kevin M. Beaver ciia Dai hoc Florida (MI) ciing edng su tie'
n hanh. Cac nha khoa hoc nay quydt dinh sir dung dir lieu vi ADN vi ld'i sdng cua nhung nghiem the tham gia nghien ciru de xdc dinh gen g&y anh huong tdi hanh vi hung tinh va ho nh&n th<iy ngudi ua bao luc deu sd hiru mdt bien the
gen MAOA.
Gen MAOA lamtang hoac giam nong dd cuanhieu chatdan truydn thdnkinh
dan tdi thayddi tarn trangvkhanh vi.Nhungngudisdhiru bie'
nthe'
genMAOA c6
xu hudng thlch bao lucva nhung bieh thenay cothetruyen sang the'
he ti6ptheo.
Cdn thuye'
t nhiem sSc thd choring nhung ngudi din dng thira nhiem sic the
Y thudng co nhirng hanh vi qua khich vi hung bao. Nam 1966, Richard -Speck
mdt ngucridanOng bi ketin tukh6sai vigie'
t lien tie'
p 7 ngudiy tddChicago.Khi xetnghiem ngudi tatha'y ngudi dandng naythira1 nhiemsactheY(1).
1.3. Anh hudngcuahormon
C6 nhieu nghien curukhang dinh anh huong cua hormon tdi hanh vi gay han.
Tieu bieu la nghien cdu cuaJames Dabbsvaedng su(1939),trong nghien cdu cua minh ho da tim ra mot luong ldn testosterone trong mau cua mdt ten gie'
t ngudi hang loat. Tiemchat nay se lam tang tinh hieu chien dddng vat.Cond con ngudi cung cd ket qua tuong tu. Khi td'ng tu nhung ke cd lucmg testosterone cao hem
chung thudng vi pham luat le nha tu nhieu hon.Sosanh trong mdt trudngdai hoc
ngudi ta th£y nhung sinh vien khd bao, vd trach nhiem xa hoi thudng cd
testosterone trungbinh caohonnhung sinh vien binh thudng kMc.
Ne'
u luong testosterone gay nen tinh hidu chien thi dan dng thudng hieu chien
nhieuhon phu nu.Chi'nh luong testosteroned dan dng caohon dagiaithich tai sao sd ddng ngudibi bdtvipham tdi bao luc thudng\k namgidi.Macduconcd nhung yd'u td khac quy dinh vd gidi nhung ro rang co su kMc biet vi mat hormon giua nam vanurco lienquan de'
Mbt minh chung ntra la su khkc bill ve giori trong bao lire gia dinh. Ngucri
chbng thudng co lugng testosteronecaohern vgva nhungngucri danbngthubngcb
xu hubrng hknhhung vgminhnhidu hon cung nhiram ski vgnhieu hon. Trongmbt cubekhao sat ve tre em cuaE. Maccoby va CorolFacklin cho kdtqua cac be trai
thirbng hieu chidn hon cac be gki. Thbng qua videquansat tro chcfi ngucri ta thly
ckcem trai c6 nhidu hanh dbng khbng thubc tr6 chcfi nhir x6 dly,dinh nhau hon
cacem gai.
Nhan dinh ve dkn bng hidu chidn cung tbn tai nhung kdt qua khkc bidt trong
db co nghien ebu cua B.A. Betncorut vk N. Miller (1996), khi phln tlch dua trdn 64cube thi nghidm cho bidt dh su that Ik trong mbt sbhoan canh nha'
t dinh, dan
bng thuemg hidu chidn hon phu nu nhimg su khac bidt giGa hai gibi se con rat it khi ca hai thucsubi khidu khfch,
Didu nay ligiai taisao ngubn gbccuahanh vi gly hknlkdo gen khbng thdli
giaidugchdtckciruemg hgpgly hkn.