Definitions of abnormality

• Statistical infrequency


  Implies that a disorder is abnormal if its frequency is more than two standard deviations away from the mean, represented on a normally-distributed bell curve. Those on either side of normal distribution are considered abnormal
• Failure to function adequately


  Proposed by Rosenhan and Seligman: if a person's current mental state is preventing them from leading a 'normal' life, alongside the associated normal levels of motivation and obedience to social norms, then such individuals may be considered as abnormal
• Deviation from social norms


  Any behaviour that does not conform to the accepted or expected standards in a culture is classified as abnormal. 
• Statistical infrequency

  a person’s trait, thinking or behaviour would be considered to be an indication of abnormality if it was found to be numerically (statistically) rare/uncommon/anomalous
• weakness of statistical infrequency

  definition does not consider that many rare behaviours are actually desirable.  For example, having a very high IQ.  According to ‘statistical infrequency’, having a very high IQ is abnormal/indicative of a mental health problem.  This suggests that statistical infrequency alone is not a valid definition of abnormality and perhaps it should be rephrased as “statistically infrequent and undesirable”.
• weakness of statistical infrequency

  some mental health problems are not statistically rare.  For example, thousands of people in the UK suffer from depression.  According to the ‘statistical infrequency’ definition, depression is not a mental health problem.  This suggests that statistical infrequency is not a valid definition of abnormality
• strength of statistical infrequency


  it has high practical application. ​For example, it is used in clinical practice as an assessment tool, forming part of formal diagnosis and also assessing the severity of an individual's symptoms. E.g. in Beck's depression inventory (BDI). A score of 30+ - which would put you in the top 5% of respondents – would indicate severe depression. ​This suggests that individuals who fall within the top 5% can be targeted for support and intervention. ​Therefore, statistical infrequency can be utilised in real world diagnosis.   
• strength of statistical infrequency


  offers an objective measure in comparison with other methods of defining abnormality.  ​This means that the definition is able to provide a non-biased perspective on what makes someone 'abnormal'.  This is due to the quantitative nature of using statistics as evidence. ​ This is a strength as it means there is a quantifiable way of defining if someone can be considered abnormal or not.  ​ Therefore, SI is likely to be one of the least biased approaches to defining abnormality, and thus is still useful in diagnoses.  
• weakness of statistical infrequency


  there is still some level of subjectivity in this definition.  This is because the cut off points are subjectively determined.  The psychologist decides the point of abnormality on the standard distribution graph.  For example, some psychologists may deem 2% to be statistically rare whilst others may deem 0.4% to be statistically rare. Therefore, this definition is deemed by some to be low in validity.   
• criteria of FFA

  • Displaying behaviours that cause observer discomfort. 
  • Exhibiting extreme signs of personal distress 
  • Irrational behaviour or behaviour that is a danger to themselves or others. 
  • Behaviours that do not conform to standard interpersonal rules (e.g. eye contact or personal space) 
• weakness of FFA

  it could be criticised for being subjective.  Another person is responsible for deciding whether an individual is functioning adequately. This is a problem because there may be differences in what each person considers to be maladaptive, meaning the diagnosis may not be reliable.  For example, someone could be perceived as showing maladaptive coping if they drink a couple of glasses of wine a night to help them relax. Others may see this behaviour as adaptive or harmless behaviour.  Therefore, the diagnosis of abnormality based on this definition is not consistent/reliable. 
• strength of FFA

  there have been attempts to create objective measures of failure to function adequately.  For example, psychologists have used the global assessment of functioning questionnaire whereas others have suggested using poor attendance data at school or work to identify individuals who are failing to function adequately.  Therefore, the suggestion that FFA is subjective has been criticised and instead FFA is seen as a valid measure of abnormality.   
• weakness of FFA


  it fails to consider individuals who appear to function adequately but are seriously disturbed and mentally unwell.  For example, Harold Shipman is a GP who killed 218 patients over 25 years.  He continued to function adequately throughout his life and therefore according to this definition, Harold Shipman would not be considered mentally unwell.  Some individuals with depression continue to function adequately and their family are often unaware that they are in fact mentally unwell.  Therefore, many psychologists question the validity of using FFA as a measure of abnormality.
• weakness of FFA

  it could lead to groups within society being discriminated against due to them appearing on the surface not functioning adequately. For example, Roman Gypsy’s don’t have a fixed address, often do not work in the same way as other members of society and are considered to have low aspirations. Their lifestyle can cause distress to others and thus they are deemed as FFA. This is a problem because it leads us to question whether FFA is an accurate definition of abnormality and also suggests FFA as a definition can have social implications. 
• strength of FFA

  it offers a threshold for help. It tends to be at the point that we cease to function adequately that we seek professional help or are noticed and referred to for help by others. This criterion means that treatment and services can be targeted to those who need them most.    
• weakness of DFSN

  It is culturally relative​. Using it to decide if a behaviour is abnormal or not, will only relate to the culture that is defining it, and may not reach the same definition in another culture.​ This is a problem because we cannot arrive at a universal definition of what is normal/abnormal behaviour using social norms, because they vary from culture to culture. This suggests that the DFSN method of defining abnormality may not be valid in all cultures. e.g. in asian and African cultures hearing voices is a good sign of high spirituality
• weakness of DFSN

  Even within a culture, the method may lack temporal validity.​  This means that what is considered abnormal behaviour today, may not be in a decades time.​ This creates an issue because if we use the DFSN method, any diagnosis could be inaccurate as it is based on what is accepted in a society at the time the diagnosis is made.
• DFSN lacking temporal validity makes the definition subjective and could lead to the wrong people receiving treatments that they do not need for behaviours.​ This suggest that the DFSN definition of abnormality lacks validity as normal and abnormal behaviours change over time. e.g. being homosexual in the 1970s was considered to be abnormal but 50 years later this is widely accepted as socially acceptable and normal
• weakness of DFSN

  the definition assumes that deviating from social norms is problematic.  Rosa Parks and Martin Luther King broke social norms.  Their actions have demonstrated the benefits of breaking social norms as such actions can lead to positive social change in society.
• Jahoda identified six categories that were commonly referred to as desirable for mental health:

  1. Good self-image​ 
  2. Drive to realise self-potential (self-actualisation)​ 
  3. Ability to cope with stress ​ 
  4. Being independent (autonomous) ​ 
  5. Having an accurate perception of reality​ 
  6. Being able to adapt to changes in the environment​

  The absence of these criteria indicates abnormality.​ The more criteria someone fails to meet, the more abnormal they are
• weakness of DFIMH

  Jahoda’s criteria is too demanding and very few people would be able to meet all of the criteria. For example, when grieving following the death of a loved one, it is very normal to experience stress and negativity. However, according to this definition, these people would be classed as abnormal, irrespective of the circumstances, which are outside their control. Therefore, some suggest that deviation from ideal mental health is low in validity as a definition of abnormality
• weakness of DFIMH

  the criteria for ideal mental health reflects Western cultural norms of psychological normality- culturally relative. For example, ‘autonomy’ is something that is valued in Western cultures but in Eastern cultures, being reliant on others or asking others before making an important decision is common practise.  Therefore, the definition of deviation from ideal mental health is culturally bias and is thus seen as low in validity
• weakness of DFIMH

  the opinion of the psychiatrist may affect the diagnosis, as the criteria are very subjective. For example, one psychiatrist may feel an individual is able to cope with stress whereas another may disagree. Therefore, when this definition is used, the diagnosis may be low in validity
• strength of DFIMH

  the criteria covers a range of features of mental health, addressing most of the reasons why someone may seek to be referred for help. It allows mental health to be discussed meaningfully amongst professionals, providing a clear checklist against which we can assess ourselves.