Definitions of abnormality

• Statistical infrequency

  Defining 'normal' or 'abnormal' based on how often we come across something
• According to the statistical definition, relatively usual behaviour or characteristic can be thought of as 'normal', and any behaviour that is unusual is 'abnormal'
• Unusual behaviours

  • Irrational fear of buttons
  • Belief that neighbours are zombies
• Normal distribution

  The majority of people's scores will cluster around the average, and the further we go above or below that average, the fewer people will attain that score
• IQ

  • Average IQ is 100
  • 68% of people have an IQ between 85 and 115
  • 2% of people have an IQ below 70
• Intellectual disability disorder (IDD)


  Diagnosis given to individuals scoring below 70 on IQ tests, as they are very unusual or 'abnormal'
• Deviation from social norms

  When a person behaves in a way that is different from how we expect people to behave, based on the norms of the culture
• Homosexuality

  • Considered abnormal in some cultures, e.g. Brunei introduced laws making sex between men punishable by stoning to death
• Antisocial personality disorder (psychopathy)

  Characterised by impulsiveness, aggression, and lack of prosocial internal standards, which is considered abnormal because it doesn't conform to our moral standards
• Failure to function adequately

  When a person can no longer cope with the demands of everyday life, such as maintaining basic standards of nutrition and hygiene, holding down a job, or maintaining relationships
• Signs of failure to function adequately

  • No longer conforming to standard interpersonal rules
  • Experiencing severe personal distress
  • Behaviour becoming irrational or dangerous to self or others
• Intellectual disability disorder

  Diagnosis given when an individual has a very low IQ and is also failing to function adequately
• Deviation from ideal mental health

  Considering what makes someone 'normal' in terms of meeting criteria for ideal mental health, rather than just what makes them 'abnormal'
• Criteria for ideal mental health

  • No symptoms or distress
  • Rational and can perceive themselves accurately
  • Self-actualise (strive to reach potential)
  • Can cope with stress
  • Have a realistic view of the world
  • Have good self-esteem and lack guilt
  • Independent of other people
  • Can successfully work, love and enjoy life