In this essay the purpose is to identify the difficulties faced by psychologists when defining and diagnosing abnormal behaviour.In regards to explaining the term abnormal this can be quite difficult because there are a wide variety and a range of behaviours shown by individuals, there is not any direct characteristics which can specifically relate to abnormality, which could then provide a correct definition for abnormal behaviour. Behaviours displayed by individuals should be judged individually to determine whether it is to be identified or classed as normal or abnormal. When deciding or making assumptions and a judgement this can be affected by different factors, mainly cultural relativism which is ‘the view that moral or ethical systems, which vary from culture to culture are all equally valid and no one system is really better than any other (allaboutphilosophy.org,2019). The mental disorders classification is also known as psychiatric nosology. It is an important issue for people who may be diagnosed and represents key aspect of psychiatry and other mental health professions. There are two established systems for classifying mental disorders which are Chapter V of ICD 10 (the International Classification of Diseases) which is produced by the World Health Organization (WHO) and DSM 5 (The Diagnostic and Statistical Manual of Mental Disorders)which is produced by the American Psychiatric Association (APA). The ICD is a classification system so that psychiatrist psychotherapist, or mental health nurses can diagnose your symptoms correctly and provide the best available treatment, it can also help individuals understand what the problem is. The ICD is a reference guide that individuals can access to learn how specific condition works, what other conditions it is related to, and what the recommended treatment is. The DSM is focussed around American research. The ICD and DSM are both useful, with many practitioners making the most informed decision by referring to both. Generally, the ICD 10 is used more for making diagnosis, whereas the DSM 5 is referred to for the research it presents. In efforts to try and define abnormality there are four main ways psychologists have determined the differences in what is considered normal behaviour and what is considered abnormal. These four ways are statistical infrequency, deviation from social norms, deviation from ideal mental health and failure to function adequately.Statistical infrequency, this method is a mathematical method in numeral form for defining abnormality, this way can statically measure characteristics. The idea of this is that within the p[population characteristics should fall within a ‘normal distribution’. Within a ‘normal distribution’ there is a curve that certain behaviour that belongs to the population would be shown to show what the population distribution is. This would then mean that there would be a central average or a mean and the remainder of the population would fall symmetrically below or above. Most of the population would fall in the middle and be considered as statistically common and the minority of the population would fall at the edges or the tail which would make them statistically rare. This statistical approach defining abnormality is a good way as it shows behaviour in numerical ways and shows a clear guideline of what is identified as normal and abnormal in statistical content where this is not opinion based but evidential, so it is not biased. However statistical infrequency has limitations between desirable and undesirable behaviour or good and bad. For example, ‘a very high iq would be an advantage and bright whereas a low iq would be seen as a disadvantage and ‘slow’., so both cannot be labelled as abnormal and under this definition would show both as abnormal therefore statistical infrequency by itself cannot be used to define abnormality and must be further analysed.Deviation from social norms, the second of four defections is reliant on the set of behaviours and moral standards of a certain culture. “Abnormality can be defined as a deviation from social norms This means that we label people as abnormal if their behaviour is different from what we accept as the norms of society” (AS Psychology, 2019). Some social norms are legal written rules, and this is called explicit whereas other social norms are implicit, and these are unwritten rules, or unspoken rules in society. If individuals break these rules, then this could be seen as deviating away from social norms and then could possibly be labelled as abnormal. There are quite a few influences when taking into account this definition for example in places Countries such as UAE, it is not normal for someone to wear short skirts or dresses due to their culture whereas in Britain it would not be seen as a problem if people wore these types of clothing. Historical content what is considered normal now might have been considered abnormal at one time for example single mothers, years ago this was not a thing but in todays society this is not something that is classed as abnormal. Age and gender if a male were seen to be wearing a dress and heels this would be classed as socially abnormal as this would not be accepted in society whereas for women this is expected. This is a good definition in regards for everyday changes and noticing psychological abnormality- so when an individual makes drastic changes from deviates expectations family and friends are able to see that there is an underlying problem. therefore, encouragement may be suggested to get the right help. Limitations are there is no obvious problem when defining as there is no universal agreement and that it is individually based from culture to culture and person to person.Deviation from ideal mental health this definition was originally suggested by Jahoda in 1958 and this was different as this was defining what is normal mental health rather than what is abnormal. Jahoda had defined six characteristics by which mental health could be measured. These included positive view of the self, capability for growth and development, accurate perception of reality, autonomy and independence, positive friendships and relationships and environmental mastery. In regards to this approach it was seen that the more of these criteria’s individuals met that the more healthier the individual was and that if individuals could not meet these criteria’s there was a chance that they were suffering, or to potentially go on to be suffering, further on from a psychological disorder. This definition will allow psychologists to notice a person’s positive functioning on mental health and then shows how an individual with ‘good’ mental health is ought to act and that anything from these six criteria suggests abnormality. This could make abnormality a little easier to diagnose as there is a set of criteria to meet however this is not as such opinion based like deviation from social norms. However, to an extent there is a degree of one’s opinion as professionals need to determine whether a person fits the criteria and in one psychiatrist’s opinion there could be no deviation, whereas in another’s there maybe deviation.Failure to function adequately the fourth definition Abnormality can be defined as a failure to function adequately. This means that any individual who is unable to cope with everyday living and demands is considered as abnormal. Using the DSM 5 psychologists will assess individuals and assess different types of levels of functioning following the Global Assessment of Functioning. The Global Assessment of Functioning is applied to by scoring and they range from 10 to 100,if an individuals was to score 10 they would be considered suicidal , whereas those who were to score 60 may be suffering from moderate anxiety or mild panic attacks and individuals who are to score 100 are considered superior. However, psychological research that was conducted by Rosenman & Seligman suggests that there are seven that define this definition which are suffering, vividness and unconventionally, unpredictable and loss of control, causes observer discomfort, maladaptiveness (danger to self), irrationality/incomprehensibility and violates moral/social standards. The limitations regarding this definition is that it does not really define abnormality, it just determines the extent of a person’s problems and the likelihood of them needing professional help. For example, an individual with OCD hand washing that behaviour could be likely to make them happy and be able to get through and cope with everyday life. Also, Maladaptivness behaviour such as drinking alcohol maybe a danger to them but it is not classed as abnormal. There can be exceptions to this definition and sometimes individuals may ac or behave ‘inadequately’ but it does not make them abnormal , so this means this definition cannot be accurately applied to all .In conclusion to all four definition is shows that there is conflict between how abnormality is defined and that according to one an individual may be normal and to another may be abnormal. Therefore, psychologists need to look a whole wider picture when diagnosing and include all aspects such as culture, circumstances, a person’s ability and other factors.