I see several reasons for that, which fall broadly in two different categories (different meaning of “why”).
The first set of reasons is grounded into evolutionary psychology, “why” being taken in “why people happen to do it, whatever it’s right or wrong”. From the genes pov, your children are your greatest asset, since what matters is not having children, but having children who reach adulthood. There has been some evidence that the value we unconsciously assign to children growth with their age (with the resources we spent ensuring they grow healthy) until they reach puberty, that’s consistent with that explanation.
The other set of reasons answer to “why should we consider killing children to be worse ?” and to that I’ve several answers :
children have a higher remaining life expectancy, so killing a 10 years old mean destroying 70 years of life expectancy, while killing a 50 years old mean destroying 30 years (well, not exactly, but not far) ;
children didn’t have as much time to enjoy life, so killing a child is unfair (some people do value fairness as a terminal value, and I’m among them) - everything else being equal, if you’ve two people and together they can live 60 years, it’s better to have 30 years each than one living 50 years and the other 10 years ;
children are more vulnerable and less able to defend themselves, and therefore deserve more protection from society ;
many people consider (and I think it holds true to a point, even if I’m not sure how much) that childhood is a part of life that is more full of joy and wonder than adulthood, so depriving someone of his childhood does more harm than depriving someone of the same amount of adult life years ;
children are more psychologically vulnerable and less able to deal with their fear/pain, it’s very rare to kill someone suddenly without any pain, so the fear/pain that precedes death is actually worse for a child.
From the genes pov, your children are your greatest asset, since what matters is not having children, but having children who reach adulthood. There has been some evidence that the value we unconsciously assign to children growth with their age (with the resources we spent ensuring they grow healthy) until they reach puberty, that’s consistent with that explanation.
The second point is important: it means young adults are more valuable than young children, yet in practice morals sway the other way, with little children being the most valued now that childhood mortality is low. More specifically, a young parent who expects to have at least one more child if this one dies should be more valuable than the child.
children have a higher remaining life expectancy
Then we should assign lower value to people the older they get. Yet it’s typically considered worse to murder a very old person than a young adult. Do you disagree?
children didn’t have as much time to enjoy life, so killing a child is unfair
That is a good point which I didn’t consider.
children are more vulnerable and less able to defend themselves
Everyone is equally unable to defend themselves against a gun, or a Death Eater with a wand. This may be relevant when you’re talking about hitting someone, but not for murder. Anyway, once you’ve murdered someone, why should it matter morally that you might have failed because he defended himself?
childhood is a part of life that is more full of joy and wonder than adulthood
I think this needs evidence. FWIW it wasn’t true in my own life, and I don’t think I’m that atypical. It also predicts a weak effect of valuing 20 year olds more than 50 year olds.
it’s very rare to kill someone suddenly without any pain
This is a plausible argument against hurting children. But do you, or others, really think that a few minutes or even hours of pain are comparable with loss of life, to the same degree that people consider killing a child to be worse than killing an adult?
Yet it’s typically considered worse to murder a very old person than a young adult.
I think that’s because the elderly are more likely to be defenceless and murdering someone defenceless is considered bad for virtue ethics reasons. But if you could save either an elder’s life or a young adult’s life I’d guess most people would say you had better save the latter.
It would make me (and perhaps others) a happier person if people saying things like “it’s worse to do X than Y” would distinguish between
doing X is a greater harm to the world than doing Y, and
doing X is better evidence that the person doing it is a Bad Person than doing Y.
[EDITED to add: Oh, and “actions that broadly resemble X tend to do greater harm to the world than actions that broadly resemble Y”. And perhaps it’s worth remarking that if you cash out “Bad Person” as “person liable to do net harm to the world”, these three correspond to a typical consequentialist’s analysis of consequentialism, virtue ethics, and deontology respectively. I am not claiming that this observation is in any way original.]
By “had better” with no qualification I meant the former and by “bad for virtue ethics reasons” I meant the latter, but yes, I should make the distinction even more explicit.
Then we should assign lower value to people the older they get. Yet it’s typically considered worse to murder a very old person than a young adult. Do you disagree?
Personally I don’t consider it really worse. In society in general, the murder of an eldery is usually considered worse because the eldery is weaker, but the accidental or “natural” (ie, disease) death of an eldery is considered much less bad than the same death of a young adult.
Everyone is equally unable to defend themselves against a gun, or a Death Eater with a wand. This may be relevant when you’re talking about hitting someone, but not for murder.
It is not relevant for the murder itself, but it is relevant overall when considering how society protects people. Large-scale effects are often delt with broad heuristics (like deontology and virtues), and children being defenseless means a deontological injunction “doing harm to children is very very bad” being justified, and that injunction will apply to murder too, even if it’s less justified there. Trying to exclude murder from the injunction will weaken it, make it much less of Schelling point, so overall I don’t think it’s something society should do.
I see several reasons for that, which fall broadly in two different categories (different meaning of “why”).
The first set of reasons is grounded into evolutionary psychology, “why” being taken in “why people happen to do it, whatever it’s right or wrong”. From the genes pov, your children are your greatest asset, since what matters is not having children, but having children who reach adulthood. There has been some evidence that the value we unconsciously assign to children growth with their age (with the resources we spent ensuring they grow healthy) until they reach puberty, that’s consistent with that explanation.
The other set of reasons answer to “why should we consider killing children to be worse ?” and to that I’ve several answers :
children have a higher remaining life expectancy, so killing a 10 years old mean destroying 70 years of life expectancy, while killing a 50 years old mean destroying 30 years (well, not exactly, but not far) ;
children didn’t have as much time to enjoy life, so killing a child is unfair (some people do value fairness as a terminal value, and I’m among them) - everything else being equal, if you’ve two people and together they can live 60 years, it’s better to have 30 years each than one living 50 years and the other 10 years ;
children are more vulnerable and less able to defend themselves, and therefore deserve more protection from society ;
many people consider (and I think it holds true to a point, even if I’m not sure how much) that childhood is a part of life that is more full of joy and wonder than adulthood, so depriving someone of his childhood does more harm than depriving someone of the same amount of adult life years ;
children are more psychologically vulnerable and less able to deal with their fear/pain, it’s very rare to kill someone suddenly without any pain, so the fear/pain that precedes death is actually worse for a child.
The second point is important: it means young adults are more valuable than young children, yet in practice morals sway the other way, with little children being the most valued now that childhood mortality is low. More specifically, a young parent who expects to have at least one more child if this one dies should be more valuable than the child.
Then we should assign lower value to people the older they get. Yet it’s typically considered worse to murder a very old person than a young adult. Do you disagree?
That is a good point which I didn’t consider.
Everyone is equally unable to defend themselves against a gun, or a Death Eater with a wand. This may be relevant when you’re talking about hitting someone, but not for murder. Anyway, once you’ve murdered someone, why should it matter morally that you might have failed because he defended himself?
I think this needs evidence. FWIW it wasn’t true in my own life, and I don’t think I’m that atypical. It also predicts a weak effect of valuing 20 year olds more than 50 year olds.
This is a plausible argument against hurting children. But do you, or others, really think that a few minutes or even hours of pain are comparable with loss of life, to the same degree that people consider killing a child to be worse than killing an adult?
I think that’s because the elderly are more likely to be defenceless and murdering someone defenceless is considered bad for virtue ethics reasons. But if you could save either an elder’s life or a young adult’s life I’d guess most people would say you had better save the latter.
It would make me (and perhaps others) a happier person if people saying things like “it’s worse to do X than Y” would distinguish between
doing X is a greater harm to the world than doing Y, and
doing X is better evidence that the person doing it is a Bad Person than doing Y.
[EDITED to add: Oh, and “actions that broadly resemble X tend to do greater harm to the world than actions that broadly resemble Y”. And perhaps it’s worth remarking that if you cash out “Bad Person” as “person liable to do net harm to the world”, these three correspond to a typical consequentialist’s analysis of consequentialism, virtue ethics, and deontology respectively. I am not claiming that this observation is in any way original.]
By “had better” with no qualification I meant the former and by “bad for virtue ethics reasons” I meant the latter, but yes, I should make the distinction even more explicit.
Personally I don’t consider it really worse. In society in general, the murder of an eldery is usually considered worse because the eldery is weaker, but the accidental or “natural” (ie, disease) death of an eldery is considered much less bad than the same death of a young adult.
It is not relevant for the murder itself, but it is relevant overall when considering how society protects people. Large-scale effects are often delt with broad heuristics (like deontology and virtues), and children being defenseless means a deontological injunction “doing harm to children is very very bad” being justified, and that injunction will apply to murder too, even if it’s less justified there. Trying to exclude murder from the injunction will weaken it, make it much less of Schelling point, so overall I don’t think it’s something society should do.