Have you fallen in love with a runner? Science may have discovered why. In a study published on Wednesday , researchers studied participants in the 2013 Robin Hood Half Marathon, charting their finishing times and comparing that to the length of their fingers.聽
According to previous studies, a lower second-finger-to-fourth-finger (2D:4D) ratio has been proven as a marker for higher sperm count in men, along with a higher level of testosterone. According to the new study, in which researchers polled 439 men, runners with a lower digit ratio performed better over the 13.1-mile distance.
鈥淎 marker of testosterone exposure is therefore associated with running ability,鈥 the study concludes, 鈥渨hich ethnographic evidence has shown to be an important attribute for hunting.鈥
The 鈥渆thnographic evidence鈥 the study refers to is primitive man鈥檚 use of distance running to hunt prey, commonly called persistence hunting. This hunting method can still be observed in disparate cultures such as the Tarahumara tribe of Northern Mexico and the Kalahari in Africa, according to the report.聽
鈥淪ince testosterone is widely associated with reproductive success, an association between testosterone and endurance running would make running prowess a reliable signal of male reproductive potential,鈥 the study says. 鈥淚t may be that women are attracted to men with the capacity to 鈥榞et,鈥 rather than those who 鈥榟ave.鈥欌
Researchers say the next step will be to test this conclusion against hunting societies.聽