INDIVIDUAL DIFFERENCES & THE BRAINIndividual differences are variables that distinguish one person from another. These individual differences are linked to biology:
CULTURAL DIFFERENCES
Most psychologists consider cultural differences to be largely learned. However, because of genes and evolution, some cultural characteristics might be inherited biologically.
Biological explanations of culture are controversial. This is because they give support to stereotypes and racism.
DEVELOPMENTAL DIFFERENCES
Biological development and maturation are covered on this page:
GENDER DIFFERENCES
Whether gender is biological or not is a very controversial topic. It's been controversial in Psychology for decades but that controversy is now all over the Internet too.
Psychologywizard is staying out of this debate. It's only an A-Level. I'm tempted to say, pick an easier biological difference to write about.
Even if we can't agree how important they are, there are some well-known biological differences between the brains of men and women:
These differences might explain gender differences. For example, men are more likely to be involved with aggression and violence (linked to testosterone) and women to suffer depression (linked to serotonin). Male superiority in mathematics has been linked to brain lateralisation - and so has the increased likelihood of autism in males.
However, critics argue all these biological differences have been exaggerated. Here's a good quote to consider: the male brain is like nothing in the world so much as a female brain - Cordelia Fine PERSONALITY DIFFERENCES
Personality traits like Extroversion and Neuroticism have been linked to brain structures by Hans Eysenck.
Extroversion is caused by a brain process known as the Ascending Reticular Activating System (ARAS). The job of the ARAS is to maintain an ideal level of alertness. If the ARAS is under-active, a person does not receive enough stimulation and needs to go looking for it in the environment. These people are extroverts: outgoing and easily bored. At the other end of the scale are the introverts, whose brains receive too much stimulation; they stay away from crowds and excitement and prefer calm and quiet.
Neuroticism is based on the Autonomic Nervous System (ANS), which enables us to respond to stress. If the ANS does its job effectively, a person will be stable, with a consistent mood and an ability to learn easily. If the ANS is inefficient, the person will be neurotic, with changeable moods and difficulty learning from experience. Eysenck (1975) later proposed a third dimension called psychotic (P) which is a trait to do with compassion and morality. High P scores show antisocial traits like selfishness, hostility and impulsivity. P is linked to hormone activity - especially testosterone.
Eysenck created a questionnaire called the Eysenck Personality Questionnaire (EPQ) to measure P, E and N scores. |
OTHER DIFFERENCES: THE EFFECT OF BRAIN DAMAGE ON PERSONALITY
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fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires... In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was "no longer Gage". |
Recreation of the injury, Gage's preserved skull and a photograph of Gage with the tamping iron, which he kept as a souvenir and called his "life-long companion"
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After he died, 12 years later, Gage's skull was preserved and studied. Modern computer-assisted design has reconstructed the damage to his brain: it was damage to the frontal lobe, which is responsible for decision-making and self-restraint.
The Gage study is often taken to show that damage to the frontal lobe changes personality. This links with the classic biological study by Raine et al. which shows that the frontal lobe was under-active in brain scans of murderers. We know that the frontal lobe (in particular, the prefrontal cortex) handles self-control and rational behaviour.
The Gage study is often taken to show that damage to the frontal lobe changes personality. This links with the classic biological study by Raine et al. which shows that the frontal lobe was under-active in brain scans of murderers. We know that the frontal lobe (in particular, the prefrontal cortex) handles self-control and rational behaviour.
However, it's not as clear-cut as that. Harlow's much-quoted description of Gage was not published until after Gage's death and Harlow didn't stay in touch with Gage for the 12 years after the accident, when Gage worked for a stagecoach company. There's no evidence from Gage's lifetime that his personality transformed. The photograph of Gage with his tamping iron doesn't look like a man who has lost the ability to behave rationally.
Is Phineas Gage another one of those psychological "urban myths"? This video draws attention to brain plasticity - the power of the brain to heal itself
APPLYING INDIVIDUAL DIFFERENCES TO REAL LIFE
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EVALUATING INDIVIDUAL DIFFERENCES
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EXEMPLAR ESSAY
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