1. Definitions of abnormality

• What are the 4 definitions of abnormality?

  • Statistical infrequency
  • Deviation from social norms
  • Failure to function adequately
  • Deviation from ideal mental health
• What does the definition of statistical infrequency suggest?

  • Abnormal behaviours are rare and there is a mathematical method for defining abnormality
  • Human attributes fall in a normal distribution within the population and there is a mean and the rest of the population fall above or below that mean
  • Standard deviation tells us how far the scores fall above or below the mean (68% of population fall 1 SD above/below the mean, 95% = 2 SD)
  • 5% of the population that fall more than 2 SD from the mean are abnormal
• Definition of standard deviation: IQ example

  • Mean IQ is 100 and the standard deviation for IQ is 15
  • 68% of the population will score 85-155 (15 above or below the mean)
  • 95% of the population will score 70-130 (30 above or below the mean)
  • Those who score 69 and under, or 131 and over are abnormal
• What does the definition of deviation from social norms suggest?

  • Abnormality is when a behaviour doesn't fit with what is socially acceptable and is dependent on the culture in which the behaviour occurs (what's abnormal in one culture is not defined as abnormal in another)
  • Important to consider how deeply entrenched the norm is embedded within the culture and how culturally important it is (slight deviations may not be abnormal if norm is not important)
  • E.g. social norm to queue, those that pass it are viewed as abnormal
  • Some are policed by laws
• What does the definition of failure to function adequately suggest?

  • When an individual isn't able to cope with everyday tasks, acknowledges people act differently if but have an inability to manage everyday life, it's abnormal
  • Rosenhan and Seligman: unpredictability, maladaptive behaviour, distress, irrationality, observer discomfort, violation of moral standards and unconventionality
  • Global Assessment of Functioning Scale: measures how well people function and considers occupational functioning
  • SZ is seen as abnormal as behaviour is distressing to others even if not personally distressing
• What does the definition of deviation from ideal mental health suggest?


  • Defined in terms of Jahoda's criteria of ideal mental health. The absence of the criteria for positive mental health indicates abnormality and a potential mental disorder
  • Suggested there were 6 criteria that needed to be fulfilled and if not fulfilled, the person will experience difficulties
  • Positive attitudes towards self, Self Actualisation, Autonomy, Resistance to Stress, Environmental Mastery, Accurate perception of reality
• Jahoda's criteria of ideal mental health (1/2)

  • Positive attitudes towards self: Linked to individual's self esteem. For ideal, positive attitude should be at a good level so the individual feels happy with themselves
  • Self actualisation: Being in a state of contentment, feeling you have become the best you can be
  • Autonomy: Having independence and self reliance. Ability to function as an individual and not depending on others
• Jahoda's criteria of ideal mental health (2/2)

  • Resistance to stress: Individual should not feel under stress, and should handle stressful situations competently
  • Environmental mastery: Individual can adopt to new situations and be at ease at all situations in their life
  • Accurate perception of reality: Focused on how the individual sees the world around them and should have a perspective like how others see the world