Social Networks and the Heritability of Migratory Behavior

A small but growing body of literature examines the relationship between genetics and human migration. These studies suggest that some DRD4 alleles, particularly 7R+, are related to migration. This is surprising from a sociological perspective, which views migration largely as a product of social and economic forces. However, social relationships with migrants, which have been theorized to influence migration by providing access to migration-specific information and resources, can also be viewed as proxies for genetic relatedness within households. This study computed intraclass correlations for five relatedness groups, along with narrow-sense heritability and environmental correlations, using a large survey of Mexicans. Shared and independent variance components were estimated using multilevel models for the relatedness groups simultaneously with sex and age components. The results indicate that strong environmental influences are exerted on young family members and, to a lesser extent, males. On the other hand, genetic relatedness plays a large role in determining migration for older migrants and females; surprisingly, this is true for both domestic and international migrants.