Here’s another explanation (a bit like taw’s). I don’t find it terribly convincing either, but I don’t see an outright refutation.
Suppose you have kin, or others whose welfare (in the relevant senses) is correlated with yours. Obviously you’ll tend to help them. How much, and how urgently? Much more when they’re in worse trouble. (As taw says, when they’re in a strong position they don’t need your help, so most likely your own more direct interests matter more to you.) So there’s value in having a mechanism that makes you care more about people you’d have cared about anyway when they’re underdogs.
Well, evolution tends to produce hacks layered on hacks, so maybe the mechanism we actually got was one for making you care about everyone more when they’re underdogs. When they’re random strangers, the effect isn’t strong enough to make you do much more than think “oh, I hope they survive”; if they’re actually enemies, it isn’t strong enough to make you switch sides (Yvain and his friends didn’t actually start sending money to al Qaeda just because there’s something a bit awesome about taking on the whole of Western civilization from a cave in Afghanistan). But when it’s someone whose welfare you really care about, it can make the difference between acting and not acting.
Note that it’s beneficial (evolutionarily, I mean) to have such a reaction not only for close kin but whenever the underdog is closer to you than the oppressors. For instance, some random person is being attacked by wolves: your genes benefit (in competition with the wolves’) if you help them survive.
Here’s another explanation (a bit like taw’s). I don’t find it terribly convincing either, but I don’t see an outright refutation.
Suppose you have kin, or others whose welfare (in the relevant senses) is correlated with yours. Obviously you’ll tend to help them. How much, and how urgently? Much more when they’re in worse trouble. (As taw says, when they’re in a strong position they don’t need your help, so most likely your own more direct interests matter more to you.) So there’s value in having a mechanism that makes you care more about people you’d have cared about anyway when they’re underdogs.
Well, evolution tends to produce hacks layered on hacks, so maybe the mechanism we actually got was one for making you care about everyone more when they’re underdogs. When they’re random strangers, the effect isn’t strong enough to make you do much more than think “oh, I hope they survive”; if they’re actually enemies, it isn’t strong enough to make you switch sides (Yvain and his friends didn’t actually start sending money to al Qaeda just because there’s something a bit awesome about taking on the whole of Western civilization from a cave in Afghanistan). But when it’s someone whose welfare you really care about, it can make the difference between acting and not acting.
Note that it’s beneficial (evolutionarily, I mean) to have such a reaction not only for close kin but whenever the underdog is closer to you than the oppressors. For instance, some random person is being attacked by wolves: your genes benefit (in competition with the wolves’) if you help them survive.