Deviation from social norms:
All societies have social norms, these are not formal laws, but are rules concerning what people expect form the behaviour of others. People who behave in a socially diviant way are considered to be anti-social or undersirable- therefor abnormal by the rest of the group.
- There is no clear line between what is abnormal deviation and what is harmless, but odd behaviour.
- Cultural relativism.This definition depends on time and culture. E.g. homosexuality used to be considered to be a mental illness.
- Social deviancy isn't always a bad thing.
Failure to function adequately: