Statistical Infrequency

• This approach relies on characteristics that can be easily measured, for example intelligence.
• The average IQ is set at 100, 68% have a score in the range from 85 to 115. Only 2% of people have a score below 70.
• Having an IQ below 70 is very rare (only 2%). This means that those below this IQ could have an intellectual disability disorder
• Strength - Real World Application

  • Used in clinical practice - both as a part of diagnosis and to assess the severity of an individual's symptoms.
  • Beck's depression inventory - A score of 30+ indicated severe depression as it is uncommon
• Limitation - Unusual could be good

  • For every person with an IQ under 70 there is one above 130 - Yet they would not be seen as abnormal for having a high IQ

  Being unusual or at one end of the scale does not necessarily make someone abnormal
• Some people benefit from being seen as abnormal such as those with a low IQ being able to access support services. However there is also a stigma attached to said lables that would harm those that can manage without support.