Statistical Infrequency

• Statistical Infrequency

  Someone mentally abnormal if the mental condition is very rare in the population, using statistics
• Normal Distribution Curve

  Populations average spread of specific characteristics e.g. Intellectual Disability Disorder (IDD) being less than 70 IQ (2% of population)
• (+) A03: Objective


  Individuals have been evaluated objectively, this is better than other definitions that focus on subjective opinion from a clinician
• (-) A03: Inconsistent in Definition

  Not all statistically rare traits are classed as abnormal, for example an IQ of 130 is just as statistically rare, but not classed as abnormal

  • NHS found that 17% of people surveyed met criteria for common mental health disorders