Abstract
We compared the variability of intelligence as measured by intelligence quotient [IQ] among serial killers to that of normal population parameters. We also assessed relationships of intelligence level to differences in crime scene methodology (organized vs. disorganized) and primary motivations (financial vs. enjoyment) relative to acts of serial murder. Documented data from 303 perpetrators were retrieved from the Radford/Florida Gulf Coast University (FGCU) Database, a unique and comprehensive source of information pertaining to serial killers. A chisquare test of variance assessed serial killer IQs relative to the normal population, and independent sample t-tests extrapolated associations among intelligence, methodology, and primary motivations. Findings indicated statistically significant differences in intelligence relative to methodological approach and motivations to serially kill. In addition, the distribution of IQ level among serial killers did not model that of the normal population.