The statistical definition of abnormality
A person’s traits, thinking or behaviour are classified as abnormal if it is rare or statistically unusual.It is necessary to be clear about how rare a trait or behaviour needs to be before we class it as abnormal. Human characteristics can be plotted on a graph of normal distribution; this is a bell shaped curve. 50% fall above the mean while 50% below the mean. A minority will fall into the top or bottom 2.5% - these individuals would be considered abnormal. Standard deviations can be used to work out the spread from the mean – anyone more than 2 SD from the mean would be considered abnormal. E.g. mean IQ is 100, the SD is 15. Anyone who scores above 130 or below 70 would be considered abnormal
Strengths
It is objective –quantitative data = reliable
Cut off point is useful = identify who needs help
Weaknesses
Over inclusive – high IQ considered abnormal. Does not take desirability into account
Under inclusive – considers depression and anxiety to be normal as these are statistically frequent, however these are considered abnormal
1 in 4 people have a mental disorder, this suggests mental illness is not rare
Cut off points may not provide help to all in need e.g. scoring 71 on a IQ test
The social norms definition of abnormality
In society we have social norms that set out guidelines for how we expect people to behave and what we see as normal. Behaviour that conforms to the norms, the customs people abide by, is considered normal. Abnormality is when someone does something that does not conform to our expectations in society. E.g. seeing someone talking to themselves is seen as abnormal, unless we realise they are using a phone
Strengths
Takes desirability into account
Accounts for cultural differences and changes over time
Keeps society functioning
Weaknesses
Less reliable and less valid – depends on culture, context, age, gender
May lead to cultural bias e.g. Calvin
Form of social control
Comparison of definitions of abnormality
Both definitions are under-inclusive
• Statistical definition – do not get diagnosed if score is within normal distribution within two standard deviations
• Social norms definition - people’s behaviour needs to stand out however many cases of depression, anxiety disorder and even eating disorders go unnoticed as the individual tries to cover up the disorder
Both definitions are over inclusive
• Statistical definition – high IQ
• Social norms definition - behaviour may ‘stand out from the crowd’ and may cause some offence to others, may depend on culture e.g. women in Catholic Ireland who had babies out of wedlock were locked up in psychiatric hospitals
The power of defining the individual is abnormal is outside of their control – power comes from others
• Social norms - reflects societies views and attitudes
• Statistical definition - based on the tests that are given for making a diagnosis
Differences
• A difference is distinguishing between what is desirable in a culture – the social norms explanation can do this whereas the statistical definition is an objective measure that does not recognise this
• The social norms definition allows people to be quickly identified as abnormal as if they are behaving in a way which defies social norms, they are deemed to be abnormal however with statistical norms definitions it is less easy to identify the abnormality as the person must be assessed more rigorously and scored assigned
• Statistical definition may be more valid as it is objective and less subjective. It is more reliable as it can be re-tested by others
A person’s traits, thinking or behaviour are classified as abnormal if it is rare or statistically unusual.It is necessary to be clear about how rare a trait or behaviour needs to be before we class it as abnormal. Human characteristics can be plotted on a graph of normal distribution; this is a bell shaped curve. 50% fall above the mean while 50% below the mean. A minority will fall into the top or bottom 2.5% - these individuals would be considered abnormal. Standard deviations can be used to work out the spread from the mean – anyone more than 2 SD from the mean would be considered abnormal. E.g. mean IQ is 100, the SD is 15. Anyone who scores above 130 or below 70 would be considered abnormal
Strengths
It is objective –quantitative data = reliable
Cut off point is useful = identify who needs help
Weaknesses
Over inclusive – high IQ considered abnormal. Does not take desirability into account
Under inclusive – considers depression and anxiety to be normal as these are statistically frequent, however these are considered abnormal
1 in 4 people have a mental disorder, this suggests mental illness is not rare
Cut off points may not provide help to all in need e.g. scoring 71 on a IQ test
The social norms definition of abnormality
In society we have social norms that set out guidelines for how we expect people to behave and what we see as normal. Behaviour that conforms to the norms, the customs people abide by, is considered normal. Abnormality is when someone does something that does not conform to our expectations in society. E.g. seeing someone talking to themselves is seen as abnormal, unless we realise they are using a phone
Strengths
Takes desirability into account
Accounts for cultural differences and changes over time
Keeps society functioning
Weaknesses
Less reliable and less valid – depends on culture, context, age, gender
May lead to cultural bias e.g. Calvin
Form of social control
Comparison of definitions of abnormality
Both definitions are under-inclusive
• Statistical definition – do not get diagnosed if score is within normal distribution within two standard deviations
• Social norms definition - people’s behaviour needs to stand out however many cases of depression, anxiety disorder and even eating disorders go unnoticed as the individual tries to cover up the disorder
Both definitions are over inclusive
• Statistical definition – high IQ
• Social norms definition - behaviour may ‘stand out from the crowd’ and may cause some offence to others, may depend on culture e.g. women in Catholic Ireland who had babies out of wedlock were locked up in psychiatric hospitals
The power of defining the individual is abnormal is outside of their control – power comes from others
• Social norms - reflects societies views and attitudes
• Statistical definition - based on the tests that are given for making a diagnosis
Differences
• A difference is distinguishing between what is desirable in a culture – the social norms explanation can do this whereas the statistical definition is an objective measure that does not recognise this
• The social norms definition allows people to be quickly identified as abnormal as if they are behaving in a way which defies social norms, they are deemed to be abnormal however with statistical norms definitions it is less easy to identify the abnormality as the person must be assessed more rigorously and scored assigned
• Statistical definition may be more valid as it is objective and less subjective. It is more reliable as it can be re-tested by others