statistical infrequency Flashcards
(14 cards)
what is meant by psychopathology?
study of psychological diseases
what is meant by defining someone’s behaviour as abnormal?
implies something undesirable and needs treatment
what are the 4 definitions of abnormality?
- statistical infrequency
- deviation from social norms
- failure to function adequately
- deviation from ideal mental health
what are the two diagnostic manuals used?
DSM-5 the American manual for diagnosing mental disorders
ICD-11 the world health organisation manual for diagnosing mental health disorders
why is it hard to define normal for psychologists?
-it is more difficult to diagnose a mental illness than a physical illness
-harder to find cause of a mental illness
-harder to agree on symptoms
define statistical infrequency?
when an individual has a characteristic that is rare enough to be classed as abnormal
e.g. being less intelligent than most of the population
what does statistical infrequency assume?
that human characteristics which can be measured will form a Normal Distribution curve
this means most scores will cluster around the mean and then reduce in frequency the further away from the mean we go
what is a normal distribution curve?
the mean, median and mode are all at the peak of the curve
give an example of a disorder that can be diagnosed using statistical infrequency?
intelligence can be measured using a normal distribution curve
average IQ is 100 and this is peak
if someone is 3 SD lower than mean, IQ is less than 70 and can be diagnosed with intellectual disability disorder
if someone is 3 SD higher than the mean, IQ is more than 130 and they are a genius
what is a strength of statistical infrequency?
takes the whole population into account so representative of whole population and generalisable
e.g. normal distribution curves are used to show how an individual characteristic compares to the WHOLE pop
why might statistical infrequency not be representative and generalisable?
no consideration of cultural or gender differences of the measurement tool
IQ tests developed to only test boys
how can desirable characteristics be a limitation of statistical infrequency?
some statistically rare characteristics can be desirable
and some common characteristics can be undesirable
e.g. Albert Einstein was a genius with a statistically rare IQ of 145 yet he isn’t abnormal as it wasn’t a psychological problem
e.g. obesity isn’t statistically infrequent since it is common but it is undesirable
what useful applications does statistical infrequency have?
useful in clinical practice as we can diagnose someone with an IQ of under 70 with an intellectual disability disorder
this person can then get help or special considerations
how is using standard deviations to categorise abnormality a limitation?
using SD is an arbitrary cut off point and inflexible
people with an IQ of 71 might also need the support of being diagnosed but they won’t get this
so definition shouldn’t be used alone as only helpful for limited cases
