added 2 research items
This study sought to identify the extent to which claims about the probable characteristics of offenders in ‘offender profiles’ were based on substantive arguments. Because Toulmin's (1958) philosophy of argument has been demonstrated as a useful way of breaking down arguments into their constituent parts (Burleson, 1979) we examined the extent to which profiles contained grounds, warrants, backing and rebuttals to support or refute various claims about offenders. Twenty-one profiles, representing a range of ‘profiling styles’, were obtained from a variety of sources. All of these had been used in major criminal investigations either in the UK or internationally. Of the nearly 4,000 claims made, nearly 80% were unsubstantiated. That is, they contained no grounds, warrant, backing or rebuttal. Moreover, less than 31% of the claims were falsifiable. We argue that (a) this demonstrates the need for a careful, systematic evaluation of profiling advice (b) Toulmin's structure is one useful method for evaluating such material and for providing a possible framework for such advice.
Two studies investigated the hypothesis that individuals are prepared to perceive ambiguous statements, when presented in the from of an ‘offender profile’, as being relatively accurate descriptions of complete strangers. Study one used a bogus profile with a real case with two distinctly different offender outcomes (one genuine, one fabricated) given to two groups of police officers (n = 24, n = 22). Over half of both groups classified the profile as accurate and, despite distinct differences between the offenders, there were no differences in accuracy ratings of the genuine offender and fabricated offender. Study two examined whether this effect transferred to a genuine profile, again using professional groups (senior police officers, n = 33; forensic professionals, n = 30). Despite receiving different offenders, over 75% of each sample rated the profile as at least somewhat accurate and over 50% as a generally or a very accurate assessment. Mean ratings of the genuine offender did not differ from ratings of the fabricated offender. The majority of individuals rated the profile as useful. These studies lend preliminary support to the hypothesis that individuals tend to construct meaning around ambiguous statements about a third party within the context of offender profiling. We suggest this might be best explained as an extension of the Barnum Effect. The methodological weaknesses of the studies are discussed, as are suggestions for future research.