It is documented that fetal exposure to sexual hormones have long lasting effects on human behavior. The second-to-fourth digit ratio is a putative marker for prenatal exposure to testosterone (compared to estrogens) while in uterus with higher relative exposure to testosterone results in lower digit ratio. Although the existing literature documents the effect of digit ratio in making various decisions, no study till date studies the effects in strategic situations – especially in conflicts. We fill in this gap by observing the effects in conflict behavior. Based on a previously obtained large representative sample of volunteer student subjects (n=920), we selectively invite subjects to the experimental laboratory if their right-hand digit ratio is in the top (High type) or bottom (Low type) tercile for their gender. Unbeknownst to the subjects, we perform a controlled match of High and Low types as opponents in a 2-person rent-seeking contest. Each subject takes part in the 15-round contest twice, once against a subject of her own type and once against a subject of the other type. We find that low digit ratio males expend significantly higher effort than their high digit ratio counterparts. In sharp contrast low digit ratio females play close to the NE effort. Interestingly, the aggressive behavior does not result in higher payoff for the low digit ratio males.