NEURAL & HORMONAL
Bio. models assume aggress. located within bio. make-up of individ. rather than environ. around them --> Research studies last 30yrs show violent criminal were high in testosterone ..castration of highly aggressive males ..stop killing/injuring innocent --> H/W relationship b/twn bio. mechanisms & aggressive behaviour not simple
Neurotransmitters = chemicals enable impulses in brain to transmitted from 1 area of brain to another --> At least two linked to A.Beh: serotonin & dopamine
Serotonin reduces aggression inhibits response emotional stimuli that lead aggression --> Low levels of serotonin=impulsive behaviour/aggression/violent suicide --> Drug (Beta-blockers or BZs) reduce serotinin increase aggression -->MANN: drug that reduced serotonin linked aggression --> Used QUESTIONNARE= lack internal validity .. DCs=SD --> findings androcentric cant generalised women b/c bio. diff. in terms of hormones (testosterone) which affects aggression.
RALEIGH: added SUPPORT import. of serotonin in aggress. .. VERVET MONKEYS--> Diets high in tryptophan (increases serotonin) decreased levs/ of aggress. --> suggests diffs. in aggress. linked to levs. of serotonin --> METHODOLOGY: NON-HUMAN study.. generalisability zoocentric --> aplication limited humans & animals bio. diff.
neural &hormonal II
BOND: raising levs. of serotonin should decrease aggress. anti-depressants S.S.R.I (e.g. Prozac) --> H/W used cautiously..side-effects..psychatrists should careful when prescribing
Link b/twn high levs. of dopamine & aggress. not as well est. as serotonin h/w evidence to suggest link exists --> E.g. anti-psychotics that reduce dopamine = low levs. of aggress. in violent deliquents --> CONTRADICTORY evidence dopamine has no effect on aggress.: SCERBA meta-analysis 29 studies (pre-1992) .. neurotransmitter levs. in anti-social children & adults --> Low levs. of serotonin in individ. described aggressive .. but no signif. rise/fall in dopamine --> reduced levs. of serotonin in all anti-social groups.. lowest in suicides --> H/W lacks historical validity b/c definition of anti-social changed... Since pre-1992 ASBOs introduced --> Evidence to suggest bio. approach REDUCTIONIST ..other factors to influence how aggress. a person is --> COUPISS: mice reward pathway.. brain opens up in response to an aggress. event (dopamine +ve reinforcer) --> Suggests we seek aggressive events b/c we get rewards --> This CONTRADICTS bio. theory b/c behavioural evidence which suggests aggression diathesis --> pre-dispostion to be aggressive but factors environment expose this trait
neural & hormonal III
Testoterone influence aggress. from young adulthood onwards due to action brain areas involved in controling aggress. --> DABBS: salivary levs. of testoterone in violent & non-violent criminals --> Those high levs. of testoterone .. history of primarily violent crime .. those low levs. commited non-violent crime --> SUPPORTED by studies non-prison populations.. LINDMAN: young males..drunk..aggressive..high testosterone levs. than those not aggressive--> H/W lack internal validity ..generalisabilty to men all ages limited = younger males have higher levs. testosterone than older males
CHALLENGE HYPOTHESIS: in monogamous species testosterone only rise above baseline breeding level in response to social challenges i.e. male-male aggression/threats to status --> KLINESMITH college students: those who interacted w/a gun had high levs. of testosterone & more aggressive than those who interacted w/toy --> H/W artificial cognitive priming & violence & aggress. usually associated w/a gun that's what raised testosterone levs.
Most studies into testosterone & aggression male P's GENDER BIAS --> ARCHER: Association b/twn testosterone & aggression higher for females than males! --> women w/higher levs. of testosterone high occupational status --> H/W high levs. testosterone hindrance.. assertive style..undermine alliance&subtle competition in female groups