AGGRESSION - genetic factors in aggressive behaviour Flashcards
(36 cards)
what is trying to determine genetic factors in aggression essentially a q in?
nature v nurture
what is the nature part?
genetic inheritance
what is the nurture part?
environmental influence
what have the researchers employed?
variety of methodological techniques
what are the type of methodological techniques?
twin studies, adoption studies, studies of individual genes and studies of violent populations
what is included in twin studies?
mz and dz twins
what are monozygotic and dizygotic twins? and how much do they share?
mz= identical share same genes and dz= non identical which share only 50 %
what do researchers compare with twins?
compare degree of similarity for a particular trait e.g aggression btw sets of mz to similarity btw sets of dz twin
what happens if mz twins more alike in terms of their aggressive behaviour?
should be due to genes than evironment both types of twins share same environment but mz more genetically alike
what have most twin studies focused on?
criminal behaviour using adult twins
what did studies find when assessing adult twins?
found that nearly 50% of the variance in direct aggressive behaviour could be attributed to genetic factors
what was the study called that assessed adult studies?
coccaro et al
what are adoption studies and what can they help with?
help untangle relative contributions to environment and heredity in aggression
what happens if positive correlation found btw aggresive b in adopted children and aggressive b in biological parents?
genetic effect implied
when will environmental be implied for adoptive children?
if positive correlation btw children and adoptive family
what study did over 14,000 adoptions?
denmark
what was found in denmark study?
significant number of adopted boys with criminal convictions had biological parents (particularly fathers)with criminal convictions e.g genetic effect
who investigated denmark study?
hutchings and mednick
what are the two types of gene for aggression?
the role of MAOA
gene environment- interaction
what is the role of MAOA?
gene possible for producing a protein called maoa has been associated with aggressive b
what does maoa regulate?
regulates metabolism of serotonin in brain and low levels of serotonin associated with impulsive aggresive b
what happened in 1980s (maoa)
study of dutch family found that many of male members behaved in a violent and aggressive manner and large proportion had been involved in serious crimes of violence e.g rape and arson- found to have abnormally low levels of maoa and defect in gene later identified
who thought of 1980s study?
brunner et al
what was the study for gene environment interaction?
caspi et al