Twin Research and Human Genetics


IGEMS: The Consortium on Interplay of Genes and Environment Across Multiple Studies

Nancy L. Pedersena1a2 c1, Kaare Christensena3, Anna K. Dahla1a10, Deborah Finkela4, Carol E. Franza5, Margaret Gatza1a2, Briana N. Horwitza12, Boo Johanssona6, Wendy Johnsona7, William S. Kremena5a8, Michael J. Lyonsa9, Bo Malmberga10, Matt McGuea11a3, Jenae M. Neiderhisera12, Inge Petersena3 and Chandra A. Reynoldsa13

a1 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden

a2 Department of Psychology, University of Southern California, Los Angeles, CA, USA

a3 The Danish Twin Registry, University of Southern Denmark, Institute of Public Health, Epidemiology, Odense C, Denmark

a4 Department of Psychology, Indiana University Southeast, New Albany, IN, USA

a5 Department of Psychiatry, University of California – San Diego, La Jolla, CA, USA

a6 Department of Psychology, University of Gothenburg, Gothenburg, Sweden

a7 Department of Psychology and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK

a8 Center of Excellence for Stress and Mental Health, VA San Diego Healthcare Center, La Jolla, CA, USA

a9 Department of Psychology, Boston University, Boston, MA, USA

a10 Institute of Gerontology, School of Health Sciences, Jönköping University, Jönköping, Sweden

a11 Department of Psychology, University of Minnesota, Minneapolis, MN, USA

a12 Department of Psychology, Penn State University, University Park, PA, USA

a13 Department of Psychology, University of California – Riverside, Riverside, CA, USA


The Interplay of Genes and Environment across Multiple Studies (IGEMS) group is a consortium of eight longitudinal twin studies established to explore the nature of social context effects and gene-environment interplay in late-life functioning. The resulting analysis of the combined data from over 17,500 participants aged 25–102 at baseline (including nearly 2,600 monogygotic and 4,300 dizygotic twin pairs and over 1,700 family members) aims to understand why early life adversity, and social factors such as isolation and loneliness, are associated with diverse outcomes including mortality, physical functioning (health, functional ability), and psychological functioning (well-being, cognition), particularly in later life.

(Received August 30 2012)

(Accepted October 11 2012)

(Online publication November 28 2012)


  • twins;
  • gene-environment interaction;
  • aging;
  • longitudinal


c1 address for correspondence: Nancy L. Pedersen, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, SE-171 77 Stockholm, Sweden. E-mail: