Firesetting in the general population: The development and validation of the Fire Setting and Fire Proclivity Scales

Purpose. The main aims of the present study were to examine the prevalence of self-reported deliberate firesetting in the community, and to develop two separate measures – the Fire Setting Scale and the Fire Proclivity Scale – to assess, respectively, the antisocial and fire interest factors associated with firesetters and the propensity of firesetters to be attracted to, aroused by, behaviourally inclined, and antisocially motivated to light fires.

Method. At Time 1, 158 participants were asked to indicate – confidentially – whether they had ever intentionally set a fire. Participants also completed the newly developed Fire Setting Scale and Fire Proclivity Scale. Around 2 weeks later, 150 of the 158 participants returned at Time 2 to complete the Fire Setting Scale and Fire Proclivity Scale again. Participants' responses at Time 1 were used to gather basic descriptive information on the newly developed measures. Participants' repeated testing at Time 2 was used to measure the reliability of the measures over time.

Results. Of participants, 11 per cent (n= 18) self-reported setting a deliberate fire. These participants were similar to non-firesetters on basic demographics although firesetters reported more behavioural problems and previous convictions for vandalism-associated offences. Both the Fire Setting Scale and Fire Proclivity Scale showed good psychometric properties and discriminated clearly between self-reported firesetters and non-firesetters. However, only one subscale from the Fire Proclivity Scale – the behavioural propensity index – entered significantly into a Discriminant Function Analysis which correctly classified participants at an overall rate of 91%.

Conclusions. The two new scales developed show promise for detecting factors associated with firesetting and may be useful for (1) detecting individuals in the community who require preventative firesetting work, and (2) measuring clinical need and intervention impact associated with firesetters in secure settings.