Understanding and Preventing Violence, Volume 2: Biobehavioral Influences (1994)
Chapter: PROSPECTS FOR FUTURE HUMAN GENETIC RESEARCH
PROSPECTS FOR FUTURE HUMAN GENETIC RESEARCH
Given the difficulty and expense—and the great importance—of collecting data on twins and adoptees, criminology would immediately benefit from more extensive and more standardized description and data analysis of existing samples. For example, it is curious that a significant genetic effect is reported for court convictions (irrespective of alcohol abuse) in Denmark but not in a similar age cohort in Sweden. Tetrachoric correlations have been reported separately for males and females in the Danish adoptee sample but not for the Stockholm sample. Complete cross-tabulations for violent crime in the Danish sample have not been reported. One inexpensive way to address these problems is to fund a meeting of the original investigators to present preplanned standardized analyses and deal with issues of replicability. Such a meeting could also lead to heuristic hypotheses about the nature of adoption preplacement effects, cross-cultural extrapolation of results, etc.
Although the issue of specialization in crime has not been fully clarified, pedigree studies of well-defined, homogeneous groups of offenders should be encouraged. There are very few direct family data on such important phenotypes as pedophiles and repetitive rapists.
Although future research might isolate one or more genetic syndromes associated with violence, polygenic influences on a number of different personality, cognitive, and psychopathological traits may be the major source of genetic predisposition to antisocial behavior. Future large-scale, epidemiological research with genetically informative samples should concentrate less on demonstrating the fact of a genetic diathesis and more on uncovering the sources of familial liability, both genetic and environmental. Consequently, data must be gathered to permit multivariate analysis involving, on the one hand, antisocial behavior and, on the other hand, personality factors such as impulsivity and sensation seeking, cognitive variables such as risk perception, and psychopathology, especially alcohol and drug abuse.
Identification of a personality trait or even a genetic locus that contributes to antisocial liability would be a major contribution to pure science, but it is not clear that such a discovery would have immediate practical applications for prevention and intervention. If genetic diathesis is multifactorial, then any single factor will be only a weak predictor. In addition, questions of genetic engineering of antisocial behavior are more appropriate
