Cochrane (1977) found that in Britain, black people were more likely to be diagnosed with schizophrenia than white people, however, this was not in countries with a majority black population, such as Jamaica, which suggests there is a diagnostic bias
This definition does not account for those who do not conform to social norms but are not abnormal, such as those that are individualistic or eccentric in their behaviour
'Failure to function adequately' as a definition of abnormality
Observable behaviour - focuses on behaviours which can be observed in the individual, allowing others to judge if the individual appears to have abnormal behaviours
Checklist - provides individuals with a practical checklist to check their behaviour
Personal perspective - allows the individual to have their own perspective of the mental disorder by recognising the personal experience of those suffering
Represents a threshold for help - provides a clear criteria for when individuals need professional help
Abnormality and dysfunction do not always go together
People with dangerous personality disorders, such as psychopaths, can appear normal, e.g. Harold Shipman a respected doctor who murdered over 200 patients but was seen as a respectable doctor
Strengths of using 'Deviation of mental health' as a definition of abnormality
Holistic - looks at the whole person and their behaviour, instead of focusing on singular behaviours
Comprehensive - includes a range of reasons as to why individuals may need help with their mental health, and a range of criteria for distinguishing mental health from illness
Positive approach - focuses on positive behaviours and what is desirable instead of undesirable behaviours
Consistent - provides a consistent and standardised measurement for those looking at both positive and negative mental health
Limitations of using 'Deviation from ideal mental health' as a definition of abnormality
It is culturally specific for western cultures, while collectivist cultures would see autonomy as undesirable
It has over demanding criteria that are often hard to achieve constantly or all of the time
It does not account for changes over time, where behaviours that were once seen as normal are now abnormal and vice versa
It tries to treat mental health in the same way as physical health, however, mental health is much more subjective and needs to be looked at in the context of the patient
Diagnosing a patient with mental health is more complex than self questionnaires and often experienced professionals struggle to come up with an accurate diagnosis
This method of defining abnormality uses an objective, standardised measure which means that it is reliable
Distribution curves are based on real data and, therefore, should be unbiased
Weaknesses
Depression is regarded as abnormal behaviour (a psychopathology) yet is so prevalent (1 in 6 adults in the UK have depression - 17% of the population) which means that it is not statistically deviant, hence using this as a measure of abnormality is unrepresentative
Having an IQ of 130 might be regarded as advantageous rather than as evidence of 'abnormality'