Biological explanations of aggression.
The role of neural and hormonal mechanisms in aggression:
Neuroanatomy:
Bard (1929)...
Raine et al. point out that brain abnormalities may create a to be violent but
they alone do not cause violent behaviour.
...
The role of neural and hormonal mechanisms in aggression:
Neuroanatomy:
Bard (1929) found that cats that had their cortex ...
Testosterone is a male hormone (present in smaller amounts in females). High
levels are associated with aggressiveness in ...
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  1. 1. Biological explanations of aggression. The role of neural and hormonal mechanisms in aggression: Neuroanatomy: Bard (1929) found that cats that had their removed displayed ‘sham rage’ (i.e. anger without the real content). This suggested that the ------------------normally inhibits the region (a sub-cortical system including the amygdala, hippocampus and hypothalamus), therefore preventing aggression. Later research implicated the in particular. Kluver and Bucy (1939) removed the temporal lobes from monkey’s brains and found that they showed little fear or (this is referred to as the Kluver –Bucy Syndrome). Electrical stimulation of the amygdala in animals increases aggression. Raine et al. (1997) used brain scans to demonstrate that were more likely to have abnormalities in their limbic system than normal individuals. In humans there is evidence that tumours in the limbic region are associated with aggressive behaviour. EG: Charles Whitman, the Texas tower sniper, was found after death to have had a that pressed on his amygdala. Evaluation: The link with aggression is complex. For example, different areas of the -------- system are associated with offensive, defensive and aggression in rats (Adams, 1986).
  2. 2. Raine et al. point out that brain abnormalities may create a to be violent but they alone do not cause violent behaviour. Neurotransmitters: Low levels of are linked to aggression, as shown, for example, by the fact that drugs which increase serotonin reduce aggression (Delville et al., 1997). Hormones: is a male hormone (present in smaller amounts in females). High levels are associated with aggressiveness in animals (e.g. Gilberto et al., 1997), however, some experiments have not shown a relationship between testosterone levels and in humans (Albert et al., 1993). High levels of adrenaline have also been linked to aggression; adrenaline is linked with the response. The female hormones and progesterone increase just before -------------------- (creating pre-menstrual tension. It has also been linked to greater hostility (Hoyenga and Hoyenga, 1993). Evaluation: has been linked to particular kinds of aggression – physical aggression (). It may amplify it, but it does not cause it (Simpson, 2001). Hormones may be an effect, rather than a cause,. Biological explanations of aggression.
  3. 3. The role of neural and hormonal mechanisms in aggression: Neuroanatomy: Bard (1929) found that cats that had their cortex removed displayed ‘sham rage’ (i.e. anger without the real emotional content). This suggested that the cortex normally inhibits the limbic region (a sub-cortical system including the amygdala, hippocampus and hypothalamus), therefore preventing aggression. Later research implicated the amygdala in particular. Kluver and Bucy (1939) removed the temporal lobes from monkey’s brains and found that they showed little fear or aggression (this is referred to as the Kluver –Bucy Syndrome). Electrical stimulation of the amygdala in animals increases aggression. Raine et al. (1997) used brain scans to demonstrate that murderers were more likely to have abnormalities in their limbic system than normal individuals. In humans there is evidence that tumours in the limbic region are associated with aggressive behaviour. EG: Charles Whitman, the Texas tower sniper, was found after death to have had a brain tumourthat pressed on his amygdala. Evaluation: The link with aggression is complex. For example, different areas of the limbic system are associated with offensive, defensive and predatory aggression in rats (Adams, 1986). Raine et al. point out that brain abnormalities may create a predisposition to be violent but they alone do not cause violent behaviour. Neurotransmitters: Low levels of serotonin are linked to aggression, as shown, for example, by the fact that drugs which increase serotonin reduce aggression (Delville et al., 1997). Hormones:
  4. 4. Testosterone is a male hormone (present in smaller amounts in females). High levels are associated with aggressiveness in animals (e.g. Gilberto et al., 1997), however, some experiments have not shown a relationship between testosterone levels and aggression in humans (Albert et al., 1993). High levels of adrenaline have also been linked to aggression; adrenaline is linked with the fight or flightresponse. The female hormones oestrogen and progesterone increase just before menstruation (creating pre-menstrual tension. It has also been linked to greater hostility (Hoyenga and Hoyenga, 1993). Evaluation: Testosterone has been linked to particular kinds of aggression – physical aggression (violence). It may amplify it, but it does not cause it (Simpson, 2001). Hormones may be an effect, rather than a cause, of aggression.

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