Dopamine receptor genes and independent versus interdependent social orientation.

Kitayama et al. make yet another stab at finding correlates of the often cited distinction of European American (more independent) and Asians (more interdependent). Their suggested genetic correlate can be compared with the environmental correlate I just noted in a recent post. Here, with the usual 'correlations are not causes' disclaimer, is their abstract:

Prior research suggests that cultural groups vary on an overarching dimension of independent versus interdependent social orientation, with European Americans being more independent, or less interdependent, than Asians. Drawing on recent evidence suggesting that the dopamine D4 receptor gene (DRD4) plays a role in modulating cultural learning, we predicted that carriers of DRD4 polymorphisms linked to increased dopamine signaling (7- or 2-repeat alleles) would show higher levels of culturally dominant social orientations, compared with noncarriers. European Americans and Asian-born Asians (total N = 398) reported their social orientation on multiple scales. They were also genotyped for DRD4. As in earlier work, European Americans were more independent, and Asian-born Asians more interdependent. This cultural difference was significantly more pronounced for carriers of the 7- or 2-repeat alleles than for noncarriers. Indeed, no cultural difference was apparent among the noncarriers. Implications for potential coevolution of genes and culture are discussed.

Given that the independent/interdependent ratio is a consequence of gene-cultural environment interaction, it is possible that some cultural effects might be moderated by specific dopamine receptor genetic variants. (Other work has suggested different alleles of the serotonin transporter gene correlate with susceptibility to stress and depression, and that serotonin 1A receptor gene polymorphism correlates with cultural difference in holistic attention.)