Anti-social behaviour is that lacking in judgement and consideration for others, ranging from careless negligence to deliberately damaging activity, vandalism and graffiti for example. Someone behaving in an anti-social manner may be a manifestation of an antisocial personality disorder.

In 2003, the United Kingdom created a scheme to lower the amount of anti-social behaviour within the nation. The law in the UK is called the Anti-Social Behaviour Act 2003.

The counter part of Anti-Social Behaviour is Pro-Social Behaviour. Pro-Social Behaviour is any behaviour intended to help or benefit another person, group or society. To determine what is Pro-Social Behaviour, we observe the underlying goal (motive) that initiates and drives the behaviour rather than the actual outcome of the behaviour. True Pro-Social behaviour is intentional.