KRM 310
Study unit 3 Biological perspectives
Testosterone: (15 marks CS)
The male sex hormone – plasma testosterone – adversely affects the central nervous system (CNS) causing
aggressive behavior and heightened libido.
Studies on monkeys indicted that testosterone was related to the aggressive behavior of monkeys. They
also indicated that testosterone levels varied with environmental condition.
Early studies found higher levels of testosterone in offenders and a STRONG link between violent male
offending and high levels of testosterone. However, these links were NOT conclusive nor as strong as had
been expected following the animal studies.
One factor which some have argued limits the usefulness of these studies on humans is that they do not
separate out differing form of aggression. They usually only consider actual physical bodily violence,
whereas human aggression is most frequently verbal.
There is a distinct difference between persons who seek out or cause violent situations and those who
defend themselves if violence is forced upon them.
The most violent rapists have very high levels of the hormone.
Antiandrogen drugs have been offered to aggressive sex offenders as an alternative to castration.
Dan Olwens:
Found a connection between testosterone and both, verbal and physical aggression.
He found that provoked aggression (a response to unfair or threatening behavior) was linked to higher
testosterone; in unprovoked aggression the relationship with testosterone was more complex.
He also found a weak, indirect relationship between testosterone and general antisocial behavior.
He concluded that testosterone was only one of many factors affecting aggression.
Daisy Schalling:
Discovered that high testosterone levels in young males were associated with verbal aggression but
not with physical aggression or fighting.
High testosterone level boys tried to protect their status by threats. They also tended to shun
monotony, to enjoy physical and competitive sports, to be more extroverted and sociable and liable to
become angry when aroused.
Low testosterone level boys would tend not to protect their position, preferring to avoid conflict and
remain silent.
Neither of the 2 studies suggest that there is a direct link between aggression and testosterone, but in
certain social circumstances those with an ability to secrete high levels of testosterone are more likely to
resort to violence or aggression.
Whether large amounts of testosterone are secreted depends upon situations in which the individual finds
himself.
Sapolsky:
Argues that it is aggression that elevates testosterone rather than the other way round, thus
suggesting that environment is more important that biology.
Biology sets the capacity for testosterone production, but that biology is meaningless without social
and environmental contexts.
Ellis and Coontz:
Note that testosterone peaks during puberty and early 20’s, which correlates with the highest crime
rates and they claim that socio-environmental researchers have failed to explain why this distribution
exists almost across all societies and cultures.
, They explain that testosterone has a strong presence in the male fetus before birth and passes into the
brain where they claim it affects development. The effects are strongest in male fetus’s as the levels of
testosterone are much higher.
Testosterone in the brain at this early stage and again later produces 3 main effects, each of which they
see as related to criminality.
1. It controls reticular arousability and thus the way in which external stimuli will be passed on to the
brain.
2. The limbic system which controls emotions (rage, love-hate, jealousy, envy and religious fervor) can
be affected by testosterone levels in the brain. Problems with the limbic area may cause sudden
and unpredictable emotions to arise, even in response to normal occurrences. These have been
linked to epilepsy and epileptic seizures and the proof for their relation to testosterone is that
these conditions are far more common in men.
3. Suggested a link between domination of a particular brain hemisphere and criminality. Heavy
reliance on the hemisphere that is least open to reason, logic and linguistic statements and most
closely related to the limbic system is claimed to be related to criminality. Reliance on this
hemisphere is more common in males than females: proof of this arises from the fact that there
are more left-handed or ambidextrous men than women in the world.
Dabbs and Dabbs:
Found that high testosterone men have a tendency towards criminal violence, aggression, delinquency,
suicide, heroic altruism, trouble with authority figures, substance abuse and excess of other kinds.
Sanches Martin:
Suggests a link between testosterone and aggression in pre-school children.
The relationship between crime, particularly aggressive crime, is sufficiently strong enough to merit further
study.
Adrenaline: (5 marks)
Adrenaline levels are outwardly shown by the level of cortical arousal.
Cortical arousal a psychological state which involves all the outward portrayals of fear or excitement –
high blood flow leading more moisture on the skin, general alertness etc.
A low level of adrenaline and a low cortical arousal are often found in those with an habitually aggressive
tendency.
Certain criminals, particularly violent criminals, take stronger stimuli to arouse them, and recover more
slowly to their normal levels than do non-criminals. They linked rapid recovery to an ability to learn from
unpleasant stimuli, including punishment, suggesting that criminals, particularly violent criminals, are less
able to learn acceptable behavior from either negative or positive stimuli.
An individual with a low cortical arousal is easily bored, becomes quickly disinterested in things and craves
exciting experiences which will suspend this state of disinterest. Normally stressful situations are not
disturbing, rather they are exciting and enjoyable, something to be savored and sought after. This alone
would not necessarily be sufficient to enhance the use of aggression: instead those who enjoy high
stimulation may turn to sport, exciting jobs or other outlets. The choice will depend on social and
environmental influences rather than on biology.
Baldwin:
Notes that all individuals enjoy stimulation at some level and that children quickly become used to
stimuli which formerly frightened them and seek other, more exciting inputs.
If a stimulus gives unpleasant results, the individual will usually learn to avoid the behavior but the
more pleasant the experience, the more quickly the child will become used to it and wish to move on
to more stimulating behaviors.
He concludes that biology may predispose to enjoyment of exciting behavior, but socialization and
environment will dictate the type of activity.