Study: Male sex drive source of conflict LONDON, Jan. 25 (UPI) -- Their "male warrior" instinct means men are programmed for aggression toward outsiders, a trait that leads to conflict, a Dutch-led study claims. The study, published in the Philosophical Transactions of the Royal Society B in Britain, suggests an evolutionary instinct for violence against others helped early men improve their status and gain more access to mates, but in modern times can translate into large-scale conflicts. This "tribal" attitude of men intended to boost their chances of reproducing is similar to the territorial behavior of chimpanzees, studies have claimed, but may not serve society well in the present day. Researchers said the "male warrior" instincts "might not be functional in modern times and are often counterproductive," Britain's Daily Telegraph reported. "A solution to conflict, which is an all-too-common problem in societies today, remains elusive," Mark van Vugt at the Vrije Universiteit in Amsterdam, who led the study, said. One reason for this might be the difficulty we have in changing our mindset, which has evolved over thousands of years. Our review of the academic literature suggests that the human mind is shaped in a way that tends to perpetuate conflict with 'outsiders.'