Development of Aggression + Antisocial Behaviour

Antisocial behaviour def (3 components)

• Disruptive, hostile or aggressive behaviour

• that violates social norms

• and harms of takes advantage of others

Aggression def

Acts intended to physically or emotionally harm others

2 ways aggression can be classified

• By goal

• By nature

2 forms of aggression (goal-based classification

• Hostile (reactive) aggression

• Instrumental (proactive) aggression

Hostile (reactive) aggression def (2)

• Goal to cause harm

• Usually in response to perceived provocation

Instrumental (proactive) aggression def + example

• Aggression as means to an end (e.g. to get a toy)

3 types of aggression by nature 

• Physical 

• Verbal

• Indirect/relational

Indirect/relational aggression def + example

Harming others through social relationships

• E.g. spreading rumours

Trajectory of aggression (4)

• Early Childhood (1–3 years): aggression (mainly instrumental physical) is common + normative

• Preschool (4–6 years): physical declines, verbal + relational aggression increases

• Middle Childhood: primarily instrumental switches to hostile, stable individual differences emerge (aggression now correlated with later-life aggression)

• Adolescence: physical aggression generally declines, but peak in self-reported serious violent crime around 16-18 (particularly males)

Child (4)-environment (4) risk-factors

• Child: difficult temperament, neurological deficits, attention difficulties, impulsivity

• Environment: common sense - household poverty, low parental education levels, neglect, or physical abuse

Biological influences: heritability + sex difference

• Moderate heritability (30-40%)

• Higher physical aggression attributed to prenatal stress (higher cortisol), higher testosterone in boys

Sex differences in aggression: physical, verbal, indirect/relational

• Physical: boys > girls (medium effect)

• Verbal: boys > girls (small effect)

• Indirect/relational: girls ≥ boys (trivial or none)

Social cognition tendencies in aggressive children

• Hostile attribution bias: interpreting others motives as hostile

• Evaluate aggressive responses more favourably

Social learning risk factors

• Aggression in children correlated with aggression in parents + older siblings, as well as parental conflict

• Aggressive children associate with aggressive children who encourage expression of aggressive behaviour (cycle)

When peer influence on aggression peaks

Adolescence

Parenting behaviours correlated with aggression development

• Harsh/punitive parenting

• Poor parental monitoring

Note on gene-environment interaction

• Genetic predispositions may only lead to aggression under certain (negative) social environmental conditions

Effectiveness of interventions in reducing aggression

• Effective