an examination of the factor structure of the psychopathy checklist

2.2.3 Instrumental-Reactive Coding Scheme
Woodworth and Porter’s (2002) instrumental-reactive coding scheme has been
used in multiple studies with violent adult offenders (e.g., Meloy, 2006; Porter &
Woodworth, 2007; Woodworth & Porter, 2002) and more recently with violent youth
offender populations (Agar, 2009; Carpenter, 2010). Further, other experts in the field
suggest this coding scheme is particularly relevant and useful in applied forensic
settings (Meloy, 2006). For example, it has been endorsed as a promising tool for
facilitating violent crime investigations. Using this coding scheme has the benefit of
ensuring comparability of our results to those found in the aforementioned Canadian
studies.
Woodworth and Porter’s instrumental-reactive coding scheme reflects Bushman
and Anderson’s (2001) contention that many acts of violence have multiple motives.
Expanding on previous dichotomous models, four separate subtypes are considered:
(a) instrumental, (b) instrumental/reactive, (c) reactive/instrumental, and (d) reactive.
For an offense to be classified as instrumental, there had to have been evidence of
some planning, and a clear goal or gain (e.g., monetary gain, revenge or retribution for
past events). In contrast, for an offense to be classified as reactive, there had to have
been evidence of anger on the part of the offender, evidence of provocation, and the
offense had to have been in response to interpersonal conflict without a cooling off
period. Index offenses classified as instrumental/reactive were primarily instrumental as
described above, but did have evidence of reactive behaviour. Index offenses
categorized as reactive/instrumental were primarily reactive as previously described, but
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