2D:4D Ratio and its relation to Aggression, Spatial Awareness and Competitiveness in individuals who play contact and non-contact sport.
Background - The length of the second and fourth digits (2D:4D) has been suggested as a marker for the prenatal androgen exposure. Relatively longer fourth finger indicates a higher prenatal androgen exposure of testosterone, a sexually dimorphic trait, which in turn gives a smaller 2D:4D ratio. Aggression, Spatial Awareness and competitiveness are associated with high levels of testosterone, therefore it is hypothesised that a relationship would occur between a low digit ratio and high levels of aggression, spatial awareness and competitiveness in a population involved in contact sports. Methods – A total of 40 QMU students who regularly participated in contact and non-contact sports were used (contact n=20, non-contact=20) in the study. All students had the second and fourth digit measured using digital calipers on each hand, and the 2D:4D ratio was calculated. Participants completed the Buss and Perry Aggression Questionnaire, which measured the individuals aggression scores. The Santa Barbara Solids Test, which measured the spatial awareness score, and a Competitiveness Questionnaire, measuring the individuals competitiveness percentage. Data was recorded on Microsoft Excel and further analysed using SPSS. Results – The study revealed that there was no statistical significance with any of the groups, however there were several trends indicating that those who participated in contact sports were more competitive than their counterparts who participated in non-contact sports. It was also noted that those who participated in non-contact sports were found to be more spatially aware, and more competitive than those involved in contact sports. Discussion – The results support the use of 2D:4D ratio as a biomarker for prenatal androgen exposure, in particular highlighting those with lower 2D:4D ratio have higher aggression levels. Although the results were not statistically significant, it does reveal a small correlation between low 2D:4D ratio and aggression. Key Words – 2D:4D ratio; Buss and Perry Questionnaire; Santa Barbara Solids Test; Competitiveness Questionnaire; Aggression; Spatial Awareness; Competitiveness