DRD4 polymorphisms modulate reward positivity and P3a in a gambling task: Exploring a genetic basis for cultural learning

Abstract

Prior work shows that people respond more plastically to environmental influences, including cultural influences, if they carry the 7 or 2‐repeat (7/2R) allelic variant of the dopamine D4 receptor gene (DRD4). The 7/2R carriers are thus more likely to endorse the norms and values of their culture. So far, however, mechanisms underlying this moderation of cultural acquisition by DRD4 are unclear. To address this gap in knowledge, we tested the hypothesis that DRD4 modulates the processing of reward cues existing in the environment. About 72 young adults, preselected for their DRD4 status, performed a gambling task, while the electroencephalogram was recorded. Principal components of event‐related potentials aligned to the Reward‐Positivity (associated with bottom‐up processing of reward prediction errors) and frontal‐P3 (associated with top‐down attention) were both significantly more positive following gains than following losses. As predicted, the gain‐loss differences were significantly larger for 7/2R carriers than for noncarriers. Also, as predicted, the cultural backgrounds of the participants (East Asian vs. European American) did not moderate the effects of DRD4. Our findings suggest that the 7/2R variant of DRD4 enhances (a) the detection of reward prediction errors and (b) controlled attention that updates the context for the reward, thereby suggesting one possible mechanism underlying the DRD4 × Culture interactions.Is there a genetic basis for cultural learning? Recent work suggests carriers of 7‐ or 2‐repeat allele of the dopamine DRD4 are more likely than non‐carriers to acquire their culture’s beliefs and practices. We show carriers are more closely attuned to reward signals compared to non‐carriers. This finding offers a possible missing link in the analysis of the co‐evolutionary dynamic between genes and culture.