Statistical infrequency


Statistical infrequency

  • Defining something as 'normal' and 'abnormal' according to how often we see it.
  • Any relatively usual behaviour can be thought of as normal and anything different to this is considered abnormal.

Example: IQ and intellectual disability disorder

  • Characteristics can be reliably measured - intelligence
  • Majority of scores will cluster around the average
  • The further we go above or below average, the fewer people will attain that score. (Normal distribution)
  • Average IQ set at 100
  • 68% have an IQ range from 85 to 115
  • Only 2% have a score below 70
  • Considered to be very unusual or abnormal and may recieve a diagnosis of IDD (previously known as mental retardation
1 of 4

Real-life application

  • Diagnosis of IDD
  • Therefore a place in thinking about normal and abnormal behaviours
  • All assessments of patients with mental disorders require some kind of measurement of how severe symptoms are compared to statistical norms.
  • Useful part of clinical assessment.
2 of 4

Unusual characteristics can be positive

  • IQ scores over 130 are just as unusual as below 70.
  • Wouldn't think of super intelligence as an undersirable characteristic that requires treatment.
  • Just because very few people display behaviours does make it statistically abnormal but doesn't mean treatment is required to return to normal.
  • Never used alone to make a diagnosis.
3 of 4

Not everyone unusual benefits from a label

  • Where someone is living a happy, fulfilled life, there is no benefit from them being labelled.
  • Someone with a very low IQ who is not distressed, can work normally, etc. would simply not need a diagnosis.
  • May have a negative effect on the way others view them.
4 of 4


No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Abnormality resources »