Numerous studies have shown that Americans of European origin have a more independent, and Asians have a more interdependent, social orientation, as measured by questionnaires asking about agreement with such statements as “I feel it is important for me to act as an independent person.” But this social-orientation difference is about 6 times greater among people from both backgrounds who are carriers of two particular alleles of a dopamine-receptor gene known as DRD4, according to a team led by Shinobu Kitayama of the University of Michigan. The alleles appear to predispose people to acquire behaviors that are considered socially desirable, the researchers say.