The Relationship Between Finger Ratio (2D:4D) and Criminal Behavior in Bipolar Disorder

ABSTRACT Objective: The purpose of this study was to examine the relationship between 2D:4D digit ratio and aggression and impulsivity in manic patients (BP) with and without a history of criminal behavior. Materials and Methods: The study included a total of 106 subjects, which included 41 healthy individuals, 34 bipolar (BP) patients with a history of criminal behavior (CBP) and 31 BP patients who had not engaged in criminal activity (NCBP). All participants were administered a socio-demographic data form, the Buss-Perry Aggression Scale (BAQ), Barratt Impulsiveness Scale-11 (BIS-11) and the Young Mania Rating Scale (YMRS) and 2D:4D ratio measurement. Results: The right hand 2D:4D ratios of BP patients included in the study were significantly lower (p: 0.007) compared to the control group. Moreover the BAQ scores of BP patients were higher compared to the control group. In CBP patients, both the right hand 2D:4D (p: 0.007) and left hand 2D:4D (p: 0.036) were significantly lower when compared to the control group. Furthermore, the BIS-11 score (p: 0.046) and YMRS (p: 0.008) of CBP patients were significantly higher when compared to NCBP. Conculusion: Based on results, we predict that in the future, the lower 2D:4D ratio in the right and left hand of bipolar manic patients who commit crimes compared to the control group, will guide in advance whether individuals prone to bipolar manic disorder will be involved in criminal activities, utilizing anatomical data (2D:4D) as the gold standard.