Deviation from social norms is a definition of abnormality. The word ‘deviation’ in this definition is referring to deviant behaviour (behaviour which is considered anti-social or undesirable by the majority of society members). In society there are social norms (standards of acceptable behaviour that are set by the social group). These standards are often in place for good reason. An example of a social norm is politeness as this is the start of interpersonal relations. People who are being rude or are behaving in an anti-social way because others find it difficult to interact with them. Social standards are not restricted to rules of etiquette but also more serious issues, such as what is acceptable in sexual behaviour. Our culture permits sex between consenting adults of any gender but regards some other behaviours as sexually deviant. For example in the past homosexuality was classified as deviant behaviour in the UK but nowadays it isn’t so things change with time.
The main difficulty with the deviation from social norms is that it varies as times change. So what is socially acceptable now may not have been acceptable 50 years ago. In our time now homosexuality is acceptable but in the past it was included under sexual and gender identity disorders. Its something like in Russia 50 years ago, anyone who disagreed with state ran the risk of being regarded as insane and placed in a mental institution. If we define abnormality in the terms of deviation from social norms then we open the door to definitions based on prevailing social morals and attitudes. This then allows mental health professionals to classify as mentally ill those individuals who transgress against social attitudes. In 1974 Szasz claimed that the concept of mental illness was simply a way to exclude nonconformists from society.
Failure to function adequately is a definition of abnormality. From an individual point of