Dopaminergic Modulation of Conscientiousness: DRD2 rs1799732 and Personality Traits in Elite Mixed Martial Arts Athletes.

Background: Personality traits, particularly Conscientiousness, are recognised as crucial psychological factors contributing to success in elite-level athletes. Emerging evidence suggests that individual differences in these traits are influenced by environmental exposure and genetic variation, especially within the dopaminergic system. The DRD2 promoter polymorphism rs1799732, which affects dopamine D2 receptor expression, may modulate goal-directed behaviour and self-regulation traits.

Methods: This study included 323 participants (141 elite mixed martial arts (MMA) athletes and 182 non-athlete controls). Participants completed the NEO Five-Factor Inventory (NEO-FFI). Genotyping for the DRD2 rs1799732 polymorphism was conducted using real-time PCR. Group comparisons and two-way ANOVA were used to assess genotype-phenotype associations and gene × environment interactions.

Results: Athletes scored significantly higher on Conscientiousness than controls. A significant main effect of the DRD2 rs1799732 genotype and a genotype × group interaction were observed for Conscientiousness. Specifically, athletes with the ins/ins genotype exhibited the highest levels of Conscientiousness, whereas individuals with the del/del genotype showed the lowest scores. No significant associations were found for other personality traits.

Conclusions: These findings suggest that the DRD2 promoter polymorphism rs1799732 moderates the expression of Conscientiousness, particularly under the structured and demanding conditions experienced by elite athletes. Our results support a gene × environment interaction model, highlighting the importance of considering genetic predispositions in high-performance environments. These insights may inform personalised psychological support strategies tailored to athletes' genetic profiles, enhancing motivation, self-regulation and long-term athletic development.