Prenatal sex hormones and the 2d: 4d digit ratio: developmental origins of heavy alcohol consumption

Introduction Prenatal testosterone and estrogen exposure determines the growth of finger length, and has also been related to later life risk taking behavior . The purpose of this study was to examine the relationship between the second (2D, index finger) and fourth (4D, ring finger) digit ratio and alcohol consumption. Methods N=448 Dutch students completed a survey on alcohol consumption. For both hands, the 2D and 4D digit lengths were measured using digital vernier calipers. The 2D: 4D digit ratio was related to alcohol consumption. In addition, alcohol consumption of subjects with a hawk - type (2D: 4D<1) and dove - type personality (2D: 4D>1) were compared. Results: The left 2D: 4D digit ratio correlated significantly (p<0.05) with the number of alcoholic drinks per week (r=-0.119) and the number of days being drunk (r=-0.121). For men, significant correlations were observed between left 2D: 4D digit ratio and drinking onset age (r=0.188), and between the right 2D: 4D digit ratio and the average number of drinks consumed per occasion (r=-0.229), number of alcoholic drinks per week (r=-0.185), and the age of regular drinking (r=0.190). For women, the left 2D: 4D digit ratio correlated significantly with the number of days being drunk (r=-0.137). Discussion & Conclusion: Prenatal sex hormone exposure seems to predict later life alcohol consumption, as subjects with a lower 2D: 4D digit ratio tend to consume greater amounts of alcohol . Although the correlations are only modest, further research into the relationship between prenatal sex hormone exposure, 2D: 4D digit ratio and alcohol consumption is warranted