Save 500 lives, 90% probability; save no lives, 10% probability.
I think it ought to be made explicit in the first scenario that 100 lives are being lost with certainty, because it’s not necessarily implied by the proposition. I know a lot of people inferred it, but the hypothetical situation never stated it was 400⁄500, so it could just as easily be 400⁄400, in which case choosing it would certianly be preferable to the second option. I think it’s important you make your hypothetical situations clear and unambiguous. Besides, a 100% probability of 100 deaths explicitly stated will influence the way people perceive the question. If you leave out writing out that 100 people are dying, you’re also subtly encouraging your readers to forget about those people as well, so it comes as little surprise that some would prefer option 1.
As MugaSofer said, it doesn’t need be 400⁄500, it may be 400⁄1,000,000 vs (500/1,000,000 with 90% probability). The original question indicated “Suppose that a disease, or a monster, or a war, or something, is killing people. ”
Imagine that hundreds of thousand lives are getting lost.
If you leave out writing out that 100 people are dying, you’re also subtly encouraging your readers to forget about those people as well, so it comes as little surprise that some would prefer option 1.
How about the following rephrasing?
There’s a natural catastrophe (e.g. a tsunami) occuring that will claim >100,000 lives. You have two options:
Save 400 lives, with certainty.
Save 500 lives, 90% probability; save no lives, 10% probability.
Or, for all we know, there are only 400 lives to be saved in the first instance. Saving 400 out of 400 is different than saving 400 out of 7 billion. The context of the proposition makes a difference, and it’s always best to be clear and unambiguous in the paramaters which will necessarily guide ones decision as to which choice is the best.
Huh. Can you clarify exactly why it matters? That is… I recognize that on a superficial level it feels like it matters, so if you’re making a point about how to manipulate human psychology, then I understand that. OTOH, if you’re making an ethical point about the value of life, I don’t quite understand why the value of those 400 lives is dependent on how many people there are in… well, in what? The world? The galaxy? The observable universe? The unobservable universe? Other?
I’m making a point about human psychology. The value of a life obviously does not change.
Although, I suppose theoretically, if the concern is not over individual lives, but over the survival of the species as a whole, and there are only 500 people to be saved, then picking the 400 option would make sense.
To clarify, that’s how many people in “The world? The galaxy? The observable universe? The unobservable universe? Other?” are going to die. You can save a maximum of 500 in this manner.
So I have a choice between
A. “Save 400 lives, allow (N-400) people to die, with certainty.” and B. “Save 500 lives (allow N-500 people to die), 90% probability; save no lives (allow N people to die), 10% probability.”
Are you suggesting that my choice between A and B ought to depend on N? If so, why?
It doesn’t depend on N if N is consistent between options A and B, but it would if they were different. It would make for an odd hypothetical scenario, but I was just saying that it’s not made completely explicit.
Save 400 lives, with certainty.
Save 500 lives, 90% probability; save no lives, 10% probability.
I think it ought to be made explicit in the first scenario that 100 lives are being lost with certainty, because it’s not necessarily implied by the proposition. I know a lot of people inferred it, but the hypothetical situation never stated it was 400⁄500, so it could just as easily be 400⁄400, in which case choosing it would certianly be preferable to the second option. I think it’s important you make your hypothetical situations clear and unambiguous. Besides, a 100% probability of 100 deaths explicitly stated will influence the way people perceive the question. If you leave out writing out that 100 people are dying, you’re also subtly encouraging your readers to forget about those people as well, so it comes as little surprise that some would prefer option 1.
As MugaSofer said, it doesn’t need be 400⁄500, it may be 400⁄1,000,000 vs (500/1,000,000 with 90% probability). The original question indicated “Suppose that a disease, or a monster, or a war, or something, is killing people. ”
Imagine that hundreds of thousand lives are getting lost.
How about the following rephrasing?
There’s a natural catastrophe (e.g. a tsunami) occuring that will claim >100,000 lives. You have two options:
Save 400 lives, with certainty.
Save 500 lives, 90% probability; save no lives, 10% probability.
I think that rephrasing improves it.
For all we know, billions of lives could be lost, with certainty; the question is how many we can save.
Or, for all we know, there are only 400 lives to be saved in the first instance. Saving 400 out of 400 is different than saving 400 out of 7 billion. The context of the proposition makes a difference, and it’s always best to be clear and unambiguous in the paramaters which will necessarily guide ones decision as to which choice is the best.
Huh.
Can you clarify exactly why it matters?
That is… I recognize that on a superficial level it feels like it matters, so if you’re making a point about how to manipulate human psychology, then I understand that.
OTOH, if you’re making an ethical point about the value of life, I don’t quite understand why the value of those 400 lives is dependent on how many people there are in… well, in what? The world? The galaxy? The observable universe? The unobservable universe? Other?
I’m making a point about human psychology. The value of a life obviously does not change.
Although, I suppose theoretically, if the concern is not over individual lives, but over the survival of the species as a whole, and there are only 500 people to be saved, then picking the 400 option would make sense.
Well, if there are only 400 people in the universe, option 1 means you’re saving them all and nobody needs die.
But that’s a rather silly interpretation. That the option 2 exists obviously means there exist at least 500 people in the universe.
I agree with all of this.
To clarify, that’s how many people in “The world? The galaxy? The observable universe? The unobservable universe? Other?” are going to die. You can save a maximum of 500 in this manner.
Um.
OK… I still seem to be missing the point.
So I have a choice between A. “Save 400 lives, allow (N-400) people to die, with certainty.” and
B. “Save 500 lives (allow N-500 people to die), 90% probability; save no lives (allow N people to die), 10% probability.”
Are you suggesting that my choice between A and B ought to depend on N?
If so, why?
It doesn’t depend on N if N is consistent between options A and B, but it would if they were different. It would make for an odd hypothetical scenario, but I was just saying that it’s not made completely explicit.
If there were only 400, where do the extra 100 come from in option 2?
That said, if this genuinely confuses you there may well be others who are having similar problems and this should be noted in the example.