Lack of evidence for allelic association between personality traits and the dopamine D4 receptor gene polymorphisms

OBJECTIVE: Personality traits in human subjects have shown considerable heritable components. Recently, two research groups reported associations between dopamine D4 receptor genotypes and the personality trait known as novelty seeking. This study was an attempt to replicate these findings. METHOD: Three different exonic dopamine D4 receptor polymorphisms were genotyped in 126 healthy Swedish subjects. Personality traits of the subjects were assessed with the Karolinska Scales of Personality. RESULTS: Although there was a tendency in the direction hypothesized, no significant association between genotype constellations and personality traits was found. CONCLUSIONS: The previously reported association between dopamine D4 receptor alleles and novelty seeking was not replicated. Possible reasons for this include differences in personality inventories, ethnicity, and type I or type II errors.