A fundamental basis for effective assessment and treatment of criminal behaviour is awareness of, and comprehensive understanding of etiological theory. This provides a core framework from which to plot the interrelationships between an offenders presented clinical phenomena and central psychological variables. Within literature relating to sexual offending, Ward and Hudson (1998) eluded to a meaningful method of conceptualising etiological theory into two types; single factor and multi factor theories (Ward & Hudson, 1998). As these figure throughout the essay, it is favourable to address each style. Single factor theories are those which focus on explaining a lone factor and its causal relationship with offending. Conversely, multifactor theories unite various single factor theories into a thorough outline of offending, providing an account of how the factors are merged to facilitate offending behaviour (Gannon, Ó Ciardha, Doley & Alleyne, 2012).
A further, and relatively underdeveloped form of theory absent from those detailed by Ward and Hudson (1998) is taxonomic classification, or typologies. Here, various offenders are subtyped into groups, based on shared motivational factors, personality characteristics, demographic aspects or a combination of each (Gannon & Pina, 2010). These classifications represent unilateral assemblage that when deemed sufficient and reliable, play an effective role in assessment and treatment, as well as feeding into more comprehensive theories of offence behaviour (Gannon et al, 2012). Because of this reason, typologies will feature at the beginning of this evaluation. Before commencing however, it is beneficial to portray what constitutes the typical firesetter.