Because a child who doesn’t find pain unpleasant is really, really handicapped, even in the modern world. The people who founded A Gift of Pain had a daughter with pain asymbolia who is now mostly blind, amongst other disabilities, through self-inflicted damage. I’m not sure whether leprosy sufferers have the no-pain or no-suffering version of pain insensitivity (I think the former) but apparently it’s the reason they suffer such damage.
This book seems to be a useful source for people considering the question of whether pain could be improved.
There may be disadvantage, yes. But it could also be that pain asymbolia is fine in a creature as high-level as a human—but without any selective fitness advantage, what would drive it to fixation in a selective sweep? Given zero reproductive advantage and possible disadvantage, it’s no surprise that it’s rare.
On the other hand, there must be some downside to pain asymbolia, or we’d all have it. (Plainly the mutation exists; why isn’t it selected for?)
Because a child who doesn’t find pain unpleasant is really, really handicapped, even in the modern world. The people who founded A Gift of Pain had a daughter with pain asymbolia who is now mostly blind, amongst other disabilities, through self-inflicted damage. I’m not sure whether leprosy sufferers have the no-pain or no-suffering version of pain insensitivity (I think the former) but apparently it’s the reason they suffer such damage.
This book seems to be a useful source for people considering the question of whether pain could be improved.
Probably because the negative feelings about the pain are what strongly motivate you to avoid it, and hence avoid physical damage.
There may be disadvantage, yes. But it could also be that pain asymbolia is fine in a creature as high-level as a human—but without any selective fitness advantage, what would drive it to fixation in a selective sweep? Given zero reproductive advantage and possible disadvantage, it’s no surprise that it’s rare.
Perhaps it is selected for, but selection hasn’t had long enough to operate to disseminate it throughout the population.