Anti-social behaviours are "age-inappropriate" actions that harm or lack consideration for the well-being of others. Many people also label behaviour which is deemed contrary to prevailing norms for social conduct as anti-social behaviour. The term is especially used in British English.
The American Psychiatric Association, in its Diagnostic and Statistical Manual of Mental Disorders, diagnoses persistent anti-social behaviour as antisocial personality disorder. The World Health Organization includes it in the International Classification of Diseases as "dissocial personality disorder". A pattern of persistent anti-social behaviours can also be present in children and adolescents diagnosed with conduct problems, including conduct disorder or oppositional defiant disorder under the DSM-5.
Intent and discrimination may determine both pro- and anti-social behaviour. Infants may act in seemingly anti-social ways and yet be generally accepted as too young to know the difference before the age of 4 or 5. Berger states that parents should teach their children that "emotions need to be regulated, not depressed". Studies have shown that in children between ages 13–14 who bully or show aggressive behavior towards others exhibits anti-social behaviors in their early adulthood. There are strong statistical relationships that shows this significant association between childhood aggressiveness and anti-social behaviors. Analyses saw that 20% of these children whom exhibits anti-social behaviors at later ages had court appearances and police contact as a result of their behavior.
Many of the studies regarding the media's influence on anti-social behaviour have been deemed inconclusive. There has been a correlation found between the number of TV hours watched and amounts of aggressive behaviour. A study was conducted that observed the effects of violent and non-violent films on Belgian and American male juvenile delinquents. The results stated that aggression increased in some measures due to the violent films, although only in those who were naturally high in aggression. Violence, racism, sexism, and other anti-social acts are attributed to things such as genetic predisposition and violence in the home. Some reviews have found strong correlations between aggression and the viewing of violent media, while others find little evidence to support their case. The only unanimously accepted truth regarding anti-social behaviour is that parental guidance carries an undoubtedly strong influence; providing children with brief negative evaluations of violent characters helps to reduce violent effects in the individual.