Looking for reward in all the wrong places: dopamine receptor gene polymorphisms indirectly affect aggression through sensation-seeking

ABSTRACT

Individuals with genotypes that code for reduced dopaminergic brain activity often exhibit a predisposition toward aggression. However, it remains largely unknown how dopaminergic genotypes may increase aggression. Lower-functioning dopamine systems motivate individuals to seek reward from external sources such as illicit drugs and other risky experiences. Based on emerging evidence that aggression is a rewarding experience, we predicted that the effect of lower-functioning dopaminergic functioning on aggression would be mediated by tendencies to seek the environment for rewards. Caucasian female and male undergraduates (N = 277) were genotyped for five polymorphisms of the dopamine D2 receptor (DRD2) gene; they reported their previous history of aggression and their dispositional reward-seeking. Lower-functioning DRD2 profiles were associated with greater sensation-seeking, which then predicted greater aggression. Our findings suggest that lower-functioning dopaminergic activity puts individuals at risk for violence because it motivates them to experience aggression’s hedonically rewarding qualities.

KEYWORDS:

• Dopamine
• aggression
• reward
• DRD2
• sensation-seeking

Acknowledgments

We thank Richard Milich for his assistance in developing the study and for his help with data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

¹ The sensation-seeking and aggression data from this sample appear in another manuscript on monoamine oxidase A (MAOA) genotypes and aggression (Chester et al., 2015). However, these data have not previously been analyzed in their relation to DRD2 genotypes.

Additional information

Funding

This research was supported by funding from the National Institutes of Health [grant number P50-DA05312] to University of Kentucky’s Center for Drug Abuse Research Translation and from University of Kentucky’s Department of Behavioral Science. The authors also gratefully acknowledge research support from the National Institutes on Drug Abuse [grant number DA007304], [grant number T32DA035200]; the National Center for Advancing Translational Sciences [grant number UL1TR000117] of the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily reflect the official views of the National Institutes of Health.