However popular this definition is it has some limitations in its way of thinking. The main objection to this approach is that there is much abnormal behaviour that is quite desirable. For example while few people have an IQ above 150, however, it is not undesirable. Similarly, there are abnormal behaviours that are undesirable. For example, 3 in 5 people in America suffer from depression. Therefore, using statistical infrequency to define abnormality means that we cannot distinguish between desirable and undesirable behaviour. In order to identify behaviours that need, there needs to be a way to identifying infrequent and undesirable behaviours.
Furthermore, behaviours differ from culture to culture. Behaviours that are statistically infrequent in one culture might be statistically frequent in another culture. For example, one of the symptoms of schizophrenia is claiming to hear voices. However, this is an experience that is regarded to be normal to and very desirable to some cultures. Even religious leaders claimed to have heard the voice of GOD speak to them.
On the other hand, it is sometimes appropriate to use statistical criterion to define abnormality. For example, mental retardation is defined in terms of normal distribution using the concept of standard deviation to establish a cut-off for abnormality. The model works better on some human behaviour than others.
Another psychological definition of the word abnormality is derivation from social norms. This model uses the concept of deviation from the sense of deviant behaviour. This is behaviour which is anti-social or undesirable. In every society there are standards of acceptable behaviour that are set by the social group. Social norms include morals as well as expectations about how people should think. These standards are often in place for good reasons. A common example of social norm is politeness. Politeness helps smooth interpersonal relations. People who are rude are behaving in an abnormal way.
Social standards are concerned with rules of etiquette as well as more serious issues such as what is acceptable in sexual behaviour. Our culture permits sex between consenting adult of any gender but regards some other as sexually deviant. For example, rape or molesting a little child. In the past around the 1970s homosexuality was regarded as deviant it is now openly regarded as normal however some people still classify it as sexually deviant. The new DSM IV contains a category called sexual and gender identity disorders, which includes paedophilia and voyeurism. These behaviours are considered to be socially deviant.
But the main difficulty with the concept of deviation from social norms is that it varies as time changes and new generations are born. For example homosexuality was not acceptable to society almost 40 years ago. In Russia 50 years ago any one who disagreed with the state was regarded as insane and thrown into a mental institution. This is not so nowadays. If we define abnormality using derivation from social norms, we will be giving a chance for definitions that rely on prevailing social norms and attitudes. There fore anyone who does not follow the rules will be susceptible to abuse. They will be incarcerated, Thomas Szasz (1974) said that mental illness was simply a way to exclude non-conformist from society.
Another difficulty of this definition is that it is bound by culture. From one culture to another and even from one society group o another society group the social norms differ. While some societies in America find homosexuality acceptable others especially in the deep south of North America find homosexuality to be an abnormal behaviour. The DSM IV is based on the dominant culture in the West (white and middleclass) and these same criteria are applied to other subcultures living in the west. For example Cochrane, 1977 said that African- Caribbean immigrants are seven times more likely to get diagnosed with schizophrenia than white.
On the bright side of things, this model distinguishes between desirable and undesirable behaviour, a feature that the statistical infrequency model did not possess. This model takes into account the effect of the behaviour on others. Deviance is defined in terms of transgression of social rules and ideally social rules are established to help people live together in peace and in harmony. Most behaviour that is deviant are socially unacceptable for the rest of us. This way of defining abnormality takes into account the greater good of the society. In a shell, abnormality is defined as a behaviour that damages others or affects others.
