agression in humans and non humans

DIFFERENCES BETWEEN NON-HUMAN AND HUMAN

AGGRESSION

According to Lorenz, aggression in non-humans is basically constructive, but in humans it becomes distorted.

Psychoanlytic Theory +Evolutionary Theory?

Konrad Lorenz looked at instinctual aggressiveness as a product of evolution.

In essence, Lorenz combined Freud's theory of aggression with Charles Darwin's natural selection theory.

In this interpretation, aggressiveness is beneficial and allows for the survival and success of populations of aggressive species since the strongest animals would eliminate weaker ones and over the course of evolution, the result would be an ultimate stronger, healthier population.

Ritualization

“Ritualisation refers to a way of discharging aggression in a fixed, stereotyped pattern.”

Fights between members of the same species result in relatively little physical harm to either victor or vanquished, but at the same time allow a victor to emerge.

E.g. Wolves will end their fight with the loser exposing its jugular vein – but this is sufficient and no blood is spilled.

Another example…The fighting that takes place between stags is highly ritualized, and the triumphant one is the male who ‘makes his point’ rather than the one who kills or incapacitates his opponent

• However naturally aggressive we are as a species compared with other species, our superior brains have enabled us to construct weapons which remove combat from the eye-to-eye, face-to-face situation.

• This inevitably reduces the overall role – and effectiveness – of appeasement rituals.

Terrosism

• Indeed, the deadliest weapons (as measured by the number of victims who can be killed or injured at one time) are the very ones which can be used at the greatest distance from the intended victims (such as bombs and intercontinental nuclear missiles). According to Lea (1984): we have developed a technology which enables our intentions to override our instincts.

Phineas Gage o Railroad worker-spike went through his

head:o Gage was able to walk away from the

accident, "talking with composure and equanimity of the hole in his head."

o Previously a polite and sociable gentleman, Gage became an antisocial, foul-mouthed, irresponsible, bad-mannered lout and unrepentant liar.

o According to his friends, he was "no longer Gage."

o He drifted from job to job, finally dying penniless.

Supporting evidence

“Common to some of the other biological theories is the proposition that aggression is the manifestation of a genetic or chemical influence. Empirical evidence shows that cerebral electrical stimulation of certain locations can induce or inhibit aggression.”

Hormones and Aggression

• Presence or absence of particular chemicals and hormones affects aggression

• E.g. high levels of the hormone testosterone and neurotransmitters such as serotonin, dopamine and noradrenalin produce higher levels of aggression in animals.

• Serotonin has been used pharmacologically as an effective treatment in combating erratic aggression. --> is this really effective?

SSRIs and Aggression

• The serotonin reuptake inhibitors (SSRIs) are prescribed for the treatment of major depressive disorder, social anxiety disorder, obsessive compulsive disorder (OCD), Eating disorders, generalized anxiety disorder, and posttraumatic stress disorder etc.

• They are generally supposed to reduce anxiety

http://www.flyfishingdevon.co.uk/salmon/year2/aggression/aggression.html#hormones_human_aggression

• Recently, there has been much interest in the possible relation between aggression and the use of SSRIs in humans

• This is due to recent murder cases in the Netherlands, where a connection was made with SSRI usage.

• The Dutch SmPCs of the SSRIs describe agitation and manic reaction as possible adverse drug reactions, but aggression and murder ideation are not described.

http://www.lareb.nl/LarebCorporateWebsite/media/publicaties/kwb_2009_3_ssris.pdf

Aggression Reports

• Paroxetine 8 cases

• Citalopram 5 cases

• Fluoxetine 4 cases

• Fluvoxamine 4 cases

• Escitalopram 2 cases

• Sertraline 1 case http://www.lareb.nl/LarebCorporateWebsite/media/publicaties/kwb_2009_3_ssris.pdf

• SSRIs increase serotonergic activity in the central nervous system by inhibition of neuronal

• reuptake of serotonin (5-hydroxy-tryptamine, 5-HT).

• Serotonin is supposed to have a role in the inhibition of impulses, the regulation of emotions and

• social functioning, which are domains linked to aggression