Firesetting
In Singer and Hensley (2004), firesetting is theorized to be a less severe or first shot at releasing aggression. Extensive periods of humiliation have been found to be present in the childhoods of several adult serial killers. These repetitive episodes of humiliation can lead to feelings of frustration and anger, which need to somehow be released in order to return to a normal state of self-worth. However, the triad combination has been questioned in this regard also, and a review has suggested that this behavior is just one that can occur in the context of childhood antisocial behavior and isn't necessarily predictive of later violence.
Read more about this topic: Macdonald Triad