Psychometric properties of the Icelandic NEO-FFI in a general population sample compared to a sample recruited for a study on the genetics of addiction.

• Published in: Personality and Individual Differences
• Main Authors: Bjornsdottir, Gyda, Jonsson, Fridrik H, Hansdottir, Ingunn, Almarsdottir, Anna B, Heimisdottir, Maria, Tyrfingsson, Thorarinn, Runarsdottir, Valgerdur A, Kristjansson, Kristleifur, Stefansson, Hreinn, Thorgeirsson, Thorgeir E
• Other Authors: DeCODE Genet, Amgen, IS-101 Reykjavik, Iceland, Univ Iceland, IS-101 Reykjavik, Iceland, Univ Iceland, Fac Psychol, Sch Hlth Sci, IS-101 Reykjavik, Iceland, SAA Natl Ctr Addict Med, Reykjavik, Iceland, Univ Iceland, Fac Pharmaceut Sci, Sch Hlth Sci, IS-101 Reykjavik, Iceland, Univ Iceland, Fac Med, Sch Hlth Sci, IS-101 Reykjavik, Iceland, Landspitali Univ Hosp, Reykjavik, Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Pergamon-Elsevier Science Ltd. 2014
• Subjects: Fíkn; Arfgengi; Ísland; Personality/classification; Behavior; Addictive; Personality Inventory/statistics & numerical data*; Genetics; Cross-Cultural Comparison*; Iceland; Social Behavior
• Online Access: http://hdl.handle.net/2336/325965; https://doi.org/10.1016/j.paid.2013.10.010

Personality traits are major determinants of social behavior influencing various diseases including addiction. Twin and family studies suggest personality and addiction to be under genetic influence. Identification of DNA susceptibility variants relies on valid and reliable phenotyping approaches. We present results of psychometric testing of the Icelandic NEO-FFI in a population sample (N=657) and a sample recruited for a study on addiction genetics (N=3,804). The Icelandic NEO-FFI demonstrated internal consistency and temporal stability. Factor analyses supported the five-factor structure. Icelandic norms were compared to American norms and language translations selected for geographical and cultural proximity to Iceland. Multiple discriminant function analysis using NEO-FFI trait scores and gender as independent variables predicted membership in recruitment groups for 47.3% of addiction study cases (N=3,804), with accurate predictions made for 69.5% of individuals with treated addiction and 43.3% of their first-degree relatives. Correlations between NEO-FFI scores and the discriminant function suggested a combination of high neuroticism, low conscientiousness and low agreeableness predicted membership in the Treated group.