Science and society: applications of behavioural genetics: outpacing the science?

Neurobiological correlates in forensic assessment: a systematic review

BACKGROUND

With the increased knowledge of biological risk factors, interest in including this information in forensic assessments is growing. Currently, forensic assessments are predominantly focused on psychosocial factors. A better understanding of the neurobiology of violent criminal behaviour and biological risk factors could improve forensic assessments.

OBJECTIVE

To provide an overview of the current evidence about biological risk factors that predispose people to antisocial and violent behaviour, and determine its usefulness in forensic assessment.

METHODS

A systematic literature search was conducted using articles from PsycINFO, Embase and Pubmed published between 2000 and 2013.

RESULTS

This review shows that much research on the relationship between genetic predisposition and neurobiological alterations with aggression is performed on psychiatric patients or normal populations. However, the number of studies comparing offenders is limited. There is still a great need to understand how genetic and neurobiological alterations and/or deficits are related to violent behaviour, specifically criminality. Most studies focus on only one of the genetic or neurobiological fields related to antisocial and/or violent behaviour. To reliably correlate the findings of these fields, a standardization of methodology is urgently needed.

CONCLUSION

Findings from the current review suggest that violent aggression, like all forms of human behaviour, both develops under specific genetic and environmental conditions, and requires interplay between these conditions. Violence should be considered as the end product of a chain of life events, during which risks accumulate and potentially reinforce each other, displaying or triggering a specific situation. This systematic review did not find evidence of predispositions or neurobiological alterations that solely explain antisocial or violent behaviour. With better designed studies, more correlation between diverse fields, and more standardisation, it might be possible to elucidate underlying mechanisms. Thus, we advocate maintaining the current case-by-case differentiated approach to evidence-based forensic assessment.

Genome-wide association studies: a primer

There have been nearly 400 genome-wide association studies (GWAS) published since 2005. The GWAS approach has been exceptionally successful in identifying common genetic variants that predispose to a variety of complex human diseases and biochemical and anthropometric traits. Although this approach is relatively new, there are many excellent reviews of different aspects of the GWAS method. Here, we provide a primer, an annotated overview of the GWAS method with particular reference to psychiatric genetics. We dissect the GWAS methodology into its components and provide a brief description with citations and links to reviews that cover the topic in detail.

Y haplogroups and aggressive behavior in a Pakistani ethnic group

Studies show that personality dimensions such as aggression are influenced by genetic factors and that allelic variants located on the Y chromosome influence such behavior. We investigated polymorphisms on the male-specific region of the human Y chromosome in 156 unrelated males from the same ethnic background, who were administered the Punjabi translation of the Buss and Perry Aggression Questionnaire that measures four aspects that constitute aggressive behavior, i.e. physical aggression, verbal aggression, anger, and hostility. A value of .85 for Cronbach's coefficient alpha indicates considerable internal consistency and suggests that the psychometric properties of the aggression questionnaire can be adapted for the Pakistani population. A mean score+/-SD of 69.70+/-19.95 was obtained for the questionnaire. Each individual was genotyped following a phylogenetic hierarchical approach to define evolutionary Y haplogroups. Five Y haplogroups that are commonly found in Eurasia and Pakistan comprised 87% (n=136) of the population sample, with one haplogroup, R1a1, constituting 55% of the sampled population. A comparison of the total and four subscale mean scores across the five common Y haplogroups that were present at a frequency > or =3% in this ethnic group revealed no overall significant differences. However, effect-size comparisons allowed us to detect an association of the haplogroups R2 (Cohen's d statistic=.448-.732) and R1a1 (d=.107-.448) with lower self-reported aggression mean scores in this population.

From genetics to genomics: ethics, policy, and parental decision-making

OBJECTIVE

Ethical evaluation of genetic testing in children is traditionally based on balancing clinical benefits and risks. However, this focus can be inconsistent with the general practice of respecting parental decision-making about their children's health care. We argue that respect for parental decision-making should play a larger role in shaping pediatric genetic testing practices, and play a similar role regarding decisions to use emerging genomic technologies.

METHODS

Genomic testing involves the examination of thousands of DNA markers spanning genes throughout the genome and their interrelationships, yielding virtually limitless interpretations. We presume that parents and providers should proceed cautiously in applying genomic testing in children, as we explore how genomic testing will stress the fault lines of the traditional ethical analysis.

RESULTS

Empirical data about the psychosocial risks and benefits of genetic testing of children do not reveal serious harms, yet virtually no such data exist yet about genomic testing. Unless empirical social and behavioral data indicate that genomic testing is highly likely to cause serious harms to the children, parental decisions to obtain comprehensive genomic testing in their children should be respected. Once comprehensive genomic testing of children becomes routine, resultant information may be more easily integrated by families than anticipated.

CONCLUSIONS

Research on the social and behavioral impact of comprehensive genomic testing on children and their families is needed to further inform parents, clinicians, and policy makers.

The expanding use of DNA in law enforcement: what role for privacy?

DNA identification methods are such an established part of our law enforcement and criminal justice systems it is hard to believe that the technologies were developed as recently as the mid-1980s, and that the databases of law enforcement profiles were established in the 1990s. Although the first databases were limited to the DNA profiles of convicted rapists and murderers, the success of these databases in solving violent crimes provided the impetus for Congress and state legislatures to expand the scope of the databases with little critical examination of each expansion's value to law enforcement or cost to privacy and civil liberties.

We are now entering a new stage of DNA forensics, in which successive database expansions over the last decade have raised the possibility of creating a population-wide repository. In addition, new applications of DNA profiling, including familial and low stringency searches, have been added to DNA dragnets, the use of medical samples for forensic analysis, and other measures to create a series of crucial, yet largely unexplored, second-generation legal and policy issues.