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Executive Cognitive Functioning (ECF) | ECF is a higher-order
cognitive construct that covers planning, initiation, and
regulation of goal-directed behavior. Cognitive abilities
included in this construct are control of attention, strategic
goal planning, abstract reasoning, cognitive flexibility,
hypothesis generation, temporal response sequencing, and the
ability to organize and adaptively utilize information contained
in working memory. The prefrontal cortex and its subcortical
circuits are thought to be the neurological substrates that
subserve ECF. People with psychiatric disorders that sometimes
entail aggressive behavior, such as antisocial personality
disorder, psychopathy, conduct disorder, and attention-deficit/hyperactivity
disorder, all show poorer performance on neuropsychological
measures of ECF. Low ECF capacity has been linked to increased
aggression in laboratory tests in preadolescents and young
adult males, increased disruptive, delinquent, and physically
aggressive behavior in adolescent females, and increased mother
and teacher reports of aggression and conduct problems. It
has been hypothesized that low ECF facilitates the expression
of aggression by decreasing behavioral inhibition and interfering
with the ability to generate alternative, nonaggressive responses
in provocative situations. It is well known that acute alcohol
consumption detrimentally affects cognitive functioning in
general. However, its predominant disruptive effects are on
ECF. Neuroimaging studies have corroborated this finding by
demonstrating that acute alcohol consumption reduces glucose
metabolism predominantly in the prefrontal cortex. Therefore,
it can be hypothesized that acute alcohol consumption disrupts
ECF, which then facilitates aggression. Recall, however, that
alcohol does not facilitate aggression in all people. It is
thus reasonable to suggest that the proposed process is more
likely to occur in those who already have low ECF.
Alcohol Expectancies | Alcohol expectancies are beliefs
about the effects of alcohol on behavior (different from placebo
effects). Some research suggests that intoxicated aggression
results, in part, from the belief that alcohol increases aggression.
It is well known that people vary in their belief that alcohol
increases arousal, power, assertiveness, verbal aggression,
and physical aggression. Significantly, self-report studies
indicate that the association between alcohol consumption
and aggression is stronger among individuals who expect alcohol
to increase aggression. Only one published laboratory study,
using the TAP, related the effects of alcohol on subjects'
aggression to their beliefs about the effects of alcohol on
aggression. Results indicated that under conditions of high
provocation, intoxicated subjects with high expectancies about
the effects of alcohol on aggression were more aggressive.
Dispositional Aggressivity | Dispositional aggressivitya
person's typical level of aggressiveness across a range of
situationsis strongly related to self-reported husband-to-wife
violence and violent behavior in college males. In addition,
as noted earlier, dispositionally aggressive individuals,
such as those with antisocial personality or conduct disorder,
show low levels of ECF. Only one study has assessed the combined
effects of acute alcohol consumption and dispositional aggressivity
on aggression as measured by the TAP. Acute alcohol consumption
increased aggression in men with high levels of dispositional
aggressivity but not in those with low or moderate levels.
Drinking History | Quantity of past alcohol consumption
is positively related to self-reported aggression in both
male and female social drinkers. Theory suggests that increased
alcohol consumption and aggressive behavior are both components
of an overarching construct of "deviant behavior."
However, the underlying mechanisms, or causal dynamics, of
that construct are not known. Moreover, one laboratory study
found that acute alcohol consumption increased aggression
on the TAP only in males with low rather than moderate or
high levels of past-year drinking. The authors hypothesized
that alcohol's detrimental effects on cognition were greater
in those with a low tolerance for alcohol compared with those
with a higher tolerance.
Biochemistry | Both animal and human research have
demonstrated a positive relation between testosterone levels
and physical aggression. A recent study found that healthy
young males with high levels of testosterone, measured from
saliva, were more aggressive on the TAP than those with low
levels. Another study reported an increase in aggressive responding
on the PSAP subsequent to the administration of testosterone
cypionate to anabolic steroid users. Heightened impulsive
aggressive behavior has also been related to a low level of
serotonin, a neurotransmitter in the brain. Interestingly,
recent studies using the TAP and the PSAP have demonstrated
increased aggression in healthy males who received a tryptophan-depleted
dietary mixture. Tryptophan is the biochemical precursor for
serotonin; its dietary depletion leads to lowered brain serotonin
levels.
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