Bullying genes

• Twins studies found 50% variance in aggressive behaviour is explained by genetic factors the other 50% is accounted for by environmental influences(shared and non-shared)
• Coccaro et al


  found that heritability of aggression depended on the type of behaviour being investigated.

  40% of the variance in direct physical violence was accounted for by genetic factors,verbal aggression was 28%
• Rhee and Waldham


  meta-analysis of adoption studies of direct aggression and anti-social behaviour.

  genetic influences accounted for 41% of the variance in aggression,same as twin studies
• The exact roles of genes in explaining aggression depend on how bullying and aggressive behaviour is defined
• The enzyme MAOA breaks down serotonin,a dysfunction in the gene can casue low levels of the enzyme
• Brunner et al


  studies 28 males in a Dutch family,all had been involved in repeated violent behaviours.All had a low activity variant of the MAOA gene and corresponding deficiency of MAOA
• Palus and Williams


  identified the dark triad as a collection of traits associated with an aversive personality.

  Machiavellianism,Narcissim and psychopathy
• Baughman et al


  all these traits are strongly correlated with bullying
• Furnhan et al


  dark triad traits are heritable,in a twin study 64% of the variation in psychopathy was explained by genetic factors,59% in narcissism and 31% machiavellianism
• Twin studies dont show us variation in behaviour as they grow up together,adoption studies allow us to see the variation as children are brought up away from biological parents
• Ball et al


  genetic influences on the risk of becoming a victim of bullying.72% for MZ and 38% for DZ.

  Greater genetic contribution to being a victim than a bully.

  Characteristics that make them vulnerable to being bullied