agression - genetic

Question 1

list all the genetic factors in aggression

Answer 1

-twin studies
-adoption studies
-the MAOA gene
gene-enviorment (GxE) interactions

Question 2

genetic factors in aggression:
what was coccaro et al’s twin study?
what did it show?

Answer 2

-suggests that heritability accounts for 50% of variance in aggressive
-EMil coccaro et al studied male monozygotic + dizygotic twins.
For aggressive beh e.g. physical assault found concordance rates of 50% for MZ twins + 19% for DZs. corresponding figures for verbal aggression were 28% MZ + 7% DZ.

Question 3

coccaro findings from twin studies

Answer 3

physical assault
50% MZ
19% DZ

verbal agression
28% MZ
7% DZ

Question 4

who studied aggression from twin studies

Answer 4

Emil coccaro et al

Question 5

which twins are 100%

Answer 5

monozygotic

Question 6

which twins are 50%

Answer 6

dizygotic

Question 7

Genetic factors in aggression:
who divides the adoption studies

Answer 7

Soo Rhee + Irwin Waldman (2002)

Question 8

genetic factors in aggression:
what would adoption studies suggest

Answer 8

similar with biological parents = genetic influence

similar with adopted parents = suggest environmental influence

Question 9

what did Rhee and Waldman do

Answer 9

meta-anaylisis of direct aggression + antisocial behaviour.

Findings= genetic influences accounted for 41% of variance in aggression similar to twin studies

Question 10

Whats the MAOA gene
(genetic factors In aggression)

Answer 10

is an enzyme.
role to ‘mop up’ neurotransmitters in the brain after nerve impulses has been transmitted from one neutron to another.
breaks down the neurotransmitter esp serotonin into constituent chemicals to be recycled.
Disfunction of this leads to abnormal activity which affects level of serotonin in the brain.

Question 11

what’s the gene-environment (GxE) interactions
(genetic factors in aggression)

Answer 11

says that low MAOA gene activity is only related to adult aggression when combined with early traumatic life events

Question 12

what’s the warrior gene?
(genetic)

Answer 12

variant of MAOA gene, leads to low MAOA activity in brain. been associated with aggressive behaviour.

Question 13

what was Bruner et al study (MAOA)

Answer 13

Brunner et al: studied 28 males of dutch family repeated involved in impulsively aggressive violent criminal behaviour e.g. rape, attempted murder, physical assault.
findings = had anomaly low levels of MAOA + low activity version of MAOA gene.

Question 14

Bruner sample

Answer 14

28 males of dutch family repeated involved in impulsively aggressive violent criminal behaviour

Question 15

Stuart et al study

Answer 15

Stuart et al: studied 97 men involved in inflicting intimate partner (IPV) violence, part of battery treatment programme.
findings= men with low-activity MAOA gene found to be most violent of IPV + inflicted worst injuries on partners

Question 16

Stuart sample

Answer 16

97 men involved in inflicting intimate partner (IPV) violence.

Question 17

what’s the study for gene-environment interactions + who

Answer 17

Frazzetto et al
found association between higher levels of antisocial aggression + low MAOA in adult males. - only the case for those who experienced significant trauma during 1st 15 years of life e.g. sexual abuse. Those who hadn’t didn’t have partially high levels off aggression as adults even if they had low MAOA.
shows= evidence of gene-enviorment interaction.

Question 18

evaluation of the genetic factors in aggression A02

Answer 18

-questions reliability:
difficult to establish how influential genes r in aggression. Because difficult to separate genetic + environmental factors.
example: McDermott et al showed Ps with low activity MAOA gene behaved aggressively in lab based money allocation game but only when provoked. Otherwise- no more or less aggressive than other Ps.

-multiple genetic factors: other genes involved in aggression. Stuart et al (IPV) study in men associated not just MAOA but also serotonin transporter gene. most likely combination of 2 genes closely linked with IPV.

-different methods of measuring aggression in studies. Incls, self-reports, parent + teacher reports, direct observation. If research finding vary depending upon how aggression is measured, then becomes difficult to draw valid conclusions about role of genetic factors.

-research support
-non-human animal studies
hypothesis that MAOA gene plays role in aggression originated with mice research. Godar et al showed MAOA knockout mice have significantly increased brain serotonin levels + are hyper aggressive.

Question 19

question reliability

Answer 19

difficult to establish how influential genes r in aggression. Because difficult to separate genetic + environmental factors.
example: McDermott et al showed Ps with low activity MAOA gene behaved aggressively in lab based money allocation game but only when provoked. Otherwise- no more or less aggressive than other Ps.

Question 20

multiple other genetic factors

Answer 20

other genes involved in aggression. Stuart et al (IPV) study in men associated not just MAOA but also serotonin transporter gene. most likely combination of 2 genes closely linked with IPV.

Question 21

different methods of measuring aggression in studies

Answer 21

Incls, self-reports, parent + teacher reports, direct observation. If research finding vary depending upon how aggression is measured, then becomes difficult to draw valid conclusions about role of genetic factors.

Question 22

research support

Answer 22

-non-human animal studies
hypothesis that MAOA gene plays role in aggression originated with mice research. Godar et al showed MAOA knockout mice have significantly increased brain serotonin levels + are hyper aggressive.