Thanks for tracking that down. I’m more sympathetic to this point of view than I was, but I think that one of its premises is unfounded. From your selection:
The sex difference in the pattern of human physical competencies, such as a longer forearm and greater upper body strength in men than in women, is also readily explained in terms of selection for male-on-male aggression, selection that involved the use of projectile and blunt force weapons (Keeley, 1996).
That citation may answer my doubt, but this argument seems to be undermined by the extensive use of weapons early homo sapiens made while hunting, a point where they diverged pretty sharply from other primates. Weapon-use was also involved in male-male aggression, yes, but it doesn’t seem overwhelmingly clear that sexual selection was the primary factor.
That citation may answer my doubt, but this argument seems to be undermined by the extensive use of weapons early homo sapiens made while hunting, a point where they diverged pretty sharply from other primates.
Other primates used weapons, too. Here is a famous one. Was the target of the first man-thrown projectile an animal while hunting, or another man? Who knows, but once one use was discovered, the second probably followed soon after.
Weapon-use was also involved in male-male aggression, yes, but it doesn’t seem overwhelmingly clear that sexual selection was the primary factor.
Sexual selection has two components: intersexual selection (mate choice based on preferences of the opposite sex) and intrasexual competition/selection (competition within members of your own sex. If weapon-use was related to male-male aggression, then it was related to the intrasexual competition component of sexual selection.
Clearly, weapon-use would be beneficial both for hunting and warfare. But I wonder if these selection pressures were stronger in warfare? Animals don’t throw spears back at you.
Furthermore, even if male weapon-use is adapted for hunting, that doesn’t necessary mean we are only seeing pressures from natural selection, not sexual selection also. As far as I remember from one of my anthropology classes, most of hunter-gatherer calories in certain societies don’t come from hunting. The hypothesis is that male hunting skills aren’t emphasized because of their importance for feeding people, which could be acted on by natural selection; rather, hunting had become yet another domain where males competed with each other to gain status and attract females. I can try to find a source on this.
Right. I don’t disagree that male-male aggression played some role. I am just uncertain about whether it exerted a stronger selection pressure than the natural selection effect of hunting ability on survival.
The sudden adoption of weapons which required upper body strength doesn’t provide much evidence to distinguish between the two.
And don’t feel obligated to go out of your way to track down sources for me; I’d prefer to know more about this issue, ceteris paribus, but I don’t think it’s terribly important in the grand scheme of things.
Thanks for tracking that down. I’m more sympathetic to this point of view than I was, but I think that one of its premises is unfounded. From your selection:
That citation may answer my doubt, but this argument seems to be undermined by the extensive use of weapons early homo sapiens made while hunting, a point where they diverged pretty sharply from other primates. Weapon-use was also involved in male-male aggression, yes, but it doesn’t seem overwhelmingly clear that sexual selection was the primary factor.
Other primates used weapons, too. Here is a famous one. Was the target of the first man-thrown projectile an animal while hunting, or another man? Who knows, but once one use was discovered, the second probably followed soon after.
Sexual selection has two components: intersexual selection (mate choice based on preferences of the opposite sex) and intrasexual competition/selection (competition within members of your own sex. If weapon-use was related to male-male aggression, then it was related to the intrasexual competition component of sexual selection.
Clearly, weapon-use would be beneficial both for hunting and warfare. But I wonder if these selection pressures were stronger in warfare? Animals don’t throw spears back at you.
Furthermore, even if male weapon-use is adapted for hunting, that doesn’t necessary mean we are only seeing pressures from natural selection, not sexual selection also. As far as I remember from one of my anthropology classes, most of hunter-gatherer calories in certain societies don’t come from hunting. The hypothesis is that male hunting skills aren’t emphasized because of their importance for feeding people, which could be acted on by natural selection; rather, hunting had become yet another domain where males competed with each other to gain status and attract females. I can try to find a source on this.
Right. I don’t disagree that male-male aggression played some role. I am just uncertain about whether it exerted a stronger selection pressure than the natural selection effect of hunting ability on survival.
The sudden adoption of weapons which required upper body strength doesn’t provide much evidence to distinguish between the two.
And don’t feel obligated to go out of your way to track down sources for me; I’d prefer to know more about this issue, ceteris paribus, but I don’t think it’s terribly important in the grand scheme of things.