Second to fourth digit ratio and male ability in sport: implications for sexual selection in humans

Fetal and adult testosterone may be important in establishing and maintaini ng sex-dependent abilities associated with male physical competitiveness. T here is evidence that the ratio of the length of the 2nd and 4th digits (2D :4D) is a negative correlate of prenatal and adult testosterone. We use abi lity in sports, and particularly ability in football, as a proxy for male p hysical competitiveness. Compared to males with high 2D:4D ratio, men with low ratio reported higher attainment in a range of sports and had higher me ntal rotation scores (a measure of visual-spatial ability). Professional fo otball players had lower 2D:4D ratios than controls. Football players in Is t team squads had lower 2D:4D than reserves or youth team players. Men who had represented their country had lower ratios than those who had not, and there was a significant (one-tailed) negative association between 2D:4D and number of international appearances after the effect of country was remove d. We suggest that prenatal and adult testosterone promotes the development and maintenance of traits which are useful in sports and athletics discipl ines and in male:male fighting. (C) 2001 Elsevier Science Inc. All rights r eserved.