Reading about the history of human warfare, starting with hunter-gatherers. Here’s something I found very interesting about patterns of lethal conflict in humans vs nonhuman animals. (All quotes from Azar Gat’s War in Human Civilization.)

Violent conflict between adult animals consists largely of display. Serious fighting does happen, but when there’s a clear winner they tend not to kill the loser, because the opponent is desperate and still armed (claws, teeth, etc). In fact, the most common form of same-species killing is against the young, who cannot fight back effectively. Pretty much universally, animals enter into lethal violent conflict only if the odds are very good – go after the young, or ambush the opponents.

Humans, as their tool use advanced, became less powerful physically. (“Homo sapiens sapiens is more slightly built than the Neanderthal and Homo erectus, who in turn were less muscled than the great apes. In short, the growth in human offensive capability was linked with a steady decrease in their natural defences.”) This has the consequence that a prepared human has a much greater advantage over an unprepared one than a prepared animal has over an unprepared one, since even an animal that just woke up will have its weapons with it. Therefore first strike confers a greater advantage to humans than in any other species.

Like animals, hunter gatherers have open pitched battles that tend to be highly ritualized – e.g. spear-throwing, for hours, that tends to kill only a handful of people – but the most lethal form of conflict, that kills the most people, is the ambush or raid wherein the primary target of killing is adult males. This makes humans very unusual.