Get access

The Dopamine D4 Receptor (DRD4) Exon 3 VNTR Contributes to Adaptive Personality Differences in an Italian Small Island Population

Authors

  • Andrea S. Camperio Ciani,

    Corresponding author
    1. Department of General Psychology, University of Padova, Padova, Italy
    • Correspondence to: Andrea S. Camperio Ciani, Department of General Psychology, University of Padova, via Venezia 8, 35131, Padova, Italy.

      E-mail: andrea.camperio@unipd.it

      Richard P. Ebstein, Psychology Department, Mt Scopus Campus, Hebrew University, Jerusalem, Israel.

      E-mail: rpebstein@gmail.com

    Search for more papers by this author
  • Shany Edelman,

    1. Department of Neurobiology, Hebrew University, Jerusalem, Israel
    Search for more papers by this author
  • Richard P. Ebstein

    Corresponding author
    1. Psychology Department, Mt Scopus Campus, Hebrew University, Jerusalem, Israel
    • Correspondence to: Andrea S. Camperio Ciani, Department of General Psychology, University of Padova, via Venezia 8, 35131, Padova, Italy.

      E-mail: andrea.camperio@unipd.it

      Richard P. Ebstein, Psychology Department, Mt Scopus Campus, Hebrew University, Jerusalem, Israel.

      E-mail: rpebstein@gmail.com

    Search for more papers by this author

Abstract

The search for evolutionary forces shaping the diversity of human personality traits encouraged studies that have found that islanders are relatively closed and introverted, with little interest in the external world. The ‘personality gene flow’ hypothesis was proposed to explain the mechanism underlying this difference, suggesting that the frequency of alleles that influence islander personality traits might progressively increase in the gene pools on islands because of selective emigration of individuals not displaying these alleles. We genotyped 96 individuals from the Italian mainland and 117 from Giglio Island, whose residents were previously assessed regarding their personality traits. We genotyped three polymorphisms: the dopamine D4 receptor (DRD4) exon 3 repeat region, the serotonin-transporter SLC6A4 5-HTTLPR indel and the dopamine transporter SLC6A3 DAT1 3′UTR repeat region. Only the DRD4 exon 3 repeat was hypothesised to show varying allele frequencies because this polymorphism could be associated with human migration and personality traits such as extraversion, openness and novelty seeking. As predicted, no differences in allele frequencies were found for the SLC6A4 and SLC6A3 polymorphisms, whereas significant differences were observed in the frequency of the DRD4 exon 3 alleles. The DRD4.2 repeat was more common in mainlanders, as expected, whereas the DRD4.7 allele was over-represented among islanders who never emigrated. This last result contradicts the suggested association of this allele with long-distance migrations. We suggest that emigration might have caused gene flow out the island that resulted in somewhat unpredictable changes in the frequencies of specific alleles, thus influencing islander personality traits. Copyright © 2013 European Association of Personality Psychology

Ancillary