doa- statistical infrequency Flashcards
What is the mathematical method for defining abnormality?
Statistical Infrequency
What definition of abnormality suggests that if something is rare then it is abnormal?
Statistical Infrequency
What does Statistical Infrequency suggest?
Suggests that abnormality should be based on infrequency- if it is rare then it is abnormal.
How does Statistical Infrequency suggest that human attributes are distributed within the population?
Normally
Explain Normal Distribution?
There is a central (mean) average, and the rest of the population fall symmetrically above and below that mean. Standard deviation tells us how far scores fall either side away from the mean.
What % of the population fall within 1 Standard Deviation from the mean?
68%
What % of the population fall within 2 Standard Deviations from the mean?
95%
Statistical infrequency suggests that what % of the population are abnormal?
- 5% of the population that fall more than two standard deviations from the mean are abnormal.
What human attribute can be used to explain Statistical Infrequency?
-IQ
What are the mean and standard deviation for the IQ?
-Mean is 100
-SD is 15
What % of the population with score between 85 and 115 on an IQ test?
68%
What % of the population will score between 70 and 130 on an IQ test?
95%
What IQ scores would be considered abnormal?
-People that score below 70 and above 130 are then considered abnormal.
What IQ means that you qualify for IDD?
70
What is the strength of the Statistical Infrequency Definition of Abnormality?
-no bias
What are the limitations of the Statistical Infrequency Definition of Abnormality?
-infrequent characteristics can be positive as well as negative
-could lead to misdiagnosis if abnormal behaviour is not rare
Explain the strength of the Statistical Infrequency Definition of Abnormality that there is no bias?
-mathematical nature of means that it is clear what is defined as abnormal and what is not.
-No opinion involved
-For example, IDD - an IQ of below 70 would be considered abnormal because this represents approx. 2.5% of the population.
-Also, for the BDI a score of 30+ is considered abnormal (top 5% of people) as this score indicates severe depression.
-This shows the value of a mathematical approach in classifying and diagnosing psychopathology such as IDD and depression- it’s useful.
Explain the limitation of the Statistical Infrequency Definition of Abnormality that infrequent characteristics can be positive as well as negative?
-For every person with an IQ below 70 there is another with an IQ above 130.
-However we would not think of someone as abnormal for having a high IQ.
-Similarly, we would not think of someone with a very low depression score on the BDI as abnormal.
-These examples show that being unusual or at one end of a psychological spectrum does not necessarily make someone abnormal.
-This means that, although statistical infrequency can form part of assessment and diagnostic procedures, it is never sufficient as the sole basis for defining abnormality.
Explain the limitation of the Statistical Infrequency Definition of Abnormality that it could lead to misdiagnosis if abnormal behaviour is not rare?
-This means that some behaviours are not statistically rare, yet still requiring intervention.
-For example, conditions like depression and anxiety are commonly occurring, and could not be considered statistically infrequent, but people that suffer with them may still need help.
-This is a limitation because this definition of abnormality assumes conditions like anxiety are not rare and therefore not abnormal, yet we know this is not the case.
