I challenge your thought that man is not as brutal. You speak of gladiators. We have the UFC which is a fight just short of death...it is a fight until loss of consciousness which is death with a heartbeat...not far from death. There are still slaves to this day...i wonder if most of the world are slaves only slaves to there desire which means they are indirectly slaves to the masters only the masters do not have to punish slaves anymore because the slaves of modern punish themselves and each other enough to keep the group in-line. The way that we go about war where we sit and press buttons and kill hundreds or thousands of people it may not seem as brutal as stabbing someone with a bayonet but i actually think dropping bombs is way more barbaric. I dont mean to take you to task but i really question whether we are more, or less, consciously aware then our ancestors were.