I see no contradiction between those claims, and am surprised that you see one.
Malthus said that human population would catch up with available resources, and since the growth in resources was slower than the growth of population, and to estimate that, we can look at how fast population grows when there are very little constraints on resources, as in North America recently colonized by Europeans. When you look at population growth in the last two million years, you’re seeing population growth with resource constraints, and yes it’s much slower, which is what Malthus is saying. It certainly doesn’t prove him wrong.
Which resource constraints? Food? Prior to the appearance of agriculture, human fossils show almost no signs of malnutrition; afterwards, malnutrition is rampant.
Furthermore, you can’t look at 17th century Europeans and draw conclusions about hunter-gatherers. For example, hunter-gatherers typically breastfeed for 5-6 years, spacing out births far more than Europeans who had access to dairy animals. They also have less body-fat, pushing the onset of menstruation back to the late teens.
Like Malthus, you are looking at post-agricultural societies and assuming that pre-agricultural societies operate in precisely the same way. This is thoroughly and completely wrong.
(Again, I am drawing from Sex at Dawn’s 11th chapter.)
Like Malthus, you are looking at post-agricultural societies and assuming that pre-agricultural societies operate in precisely the same way. This is thoroughly and completely wrong.
I bloody well am not.
I’m just saying that the numbers you show (population growth in 150 years of recently-colonized US; population growth in two million years of prehistoric humanity) do not show malthus wrong. Sure there are some things that Malthus didn’t know, and his model of reality was probably less accurate than ours. If you went back in time and showed him those numbers, and those numbers only, he would shrug and say “so what?”.
So this:
So that’s Malthus off by a factor of 10,000 on human population growth rates. On that basis, I’m quite comfortable accepting the conclusion that his theory of population growth was wrong.
Sure there are some things that Malthus didn’t know, and his model of reality was probably less accurate than ours.
Is there some meaning of “wrong” which does not involve inaccurate models?
Malthus claimed that human population doubled every 25 years unless limited in some way by the amount of available food.
So if there had been some span of time during which the human population was not limited in any way by a scarcity of available food and did not double at that rate, then that would be evidence that directly contradicts his theory.
There is, in fact, such a span of time. As I have pointed out, for two million years of human existence, there is no substantial evidence of famine. And yet the population did not double at Malthus’s proposed rate. Or ten times his proposed rate. Or a hundred times his proposed rate. In what way is he not wrong?
That is a flawed argument, WrongBot. Visible signs of starvation aren’t necessary to assume humans were living along Malthusian limits. Rates of violence were extremely high amongst hunter gatherers (homicide was the most common cause of death). According to Stephen Pinker, 20-60% of males were murdered. This shouldn’t surprise those of us who understand human nature, people will gladly start killing each other before they let themselves starve to death.
In addition, females menstruating less is a natural response to malthusian conditions. The malthusian limits wouldn’t look like hungry bodies, it would look like fewer pregnant women per year, and more murders.
That probably tells me all I need to know about Ryan and Jetha. I’ll read them, but if they dislike Pinker’s conclusions rather than his writing style they probably don’t like rationality much as I understand the term, as he’s the only mainstream academic I’m aware of who visibly demonstrates the full suite of traditional rationalist virtues in essentially all of his writing. As you might guess, I’m a big fan of traditional rationalist virtues, but as you might not know unless you have seen me speak recently, I’m also a fan of those who energetically reject them, so this should be fun.
Their primary issue with him is not his writing style or his conclusions: it’s that he blatantly misrepresents anthropological data to support his bottom-line conclusions.
For example, the way he claims that “20-60% of males were murdered” in hunter-gatherer societies in order to support the superhappy conclusion that human societies are becoming less violent over time.
For example, the way he claims that “20-60% of males were murdered” in hunter-gatherer societies in order to support the superhappy conclusion that human societies are becoming less violent over time.
Wait, what exactly is wrong with this claim? If large percentages of the male population were murdered that are no longer being murdered, how is that not “less violent”?
If you’re going to address that point in your next post, then no rush.
I’ll be covering this in the next post, but the very short version is that it isn’t his reasoning, it’s that the 20-60% number is derived in an incredibly misleading way; there is substantial anthropological and fossil evidence that he is off by at least an order of magnitude.
Much less than 2% to 6% of modern people are murdered. If, as you claim, the numbers were an order of magnitude lower than Pinker’s claim, the number of homicide deaths would still be an order of magnitude higher than the current global average of about 8 per 100,000 per year.
ETA: Thats a good point FAWS, thanks. I changed it.
8 per 100,000 would be per year, not per lifetime. Assuming an average life span of 70 years that would be about 0.56%, just about one order of magnitude lower.
there is substantial anthropological and fossil evidence that he is off by at least an order of magnitude.
It was a one sentence comment. I’m starting to worry about this community’s ability to argue in good faith.
(This criticism is not necessarily directed at you, knb; it’s not a preposterously unlikely mistake, and I know I’ve made errors of this type. It’s their frequency on LessWrong that’s starting to get to me.)
I am having difficulty with this thread. As I understand biology:
all organisms (not just humans) tend to be able to produce more offspring then the environment can support
those individuals that produce the most living (and reproducing) offspring have their genes in higher frequency in the population
therefore natural selection works and populations evolve
Both Darwin and Wallace crystallized their ideas on evolve after reading Malthus. It doesn’t matter if Malthus was wrong on some minor points—his general idea is one of the foundations of evolution by natural selection. If you throw out Malthus’ general idea then you throw out natural selection. You cannot have it both ways.
Also, the idea that famine did not occur throughout human history is naive.
Malthus claimed that human population doubled every 25 years unless limited in some way by the amount of available food.
So if there had been some span of time during which the human population was not limited in any way by a scarcity of available food and did not double at that rate, then that would be evidence that directly contradicts his theory.
Are you reading Malthus, or just listening to the little caricature of Malthus in your head and the popular media? Your own link doesn’t even say that!
“In the United States of America, where the means of subsistence have
been more ample, the manners of the people more pure, and consequently the checks to early marriages fewer, than in any of the modern states of Europe, the population has been found to double itself in twenty-five years.”
Basic grammar tells me that Malthus enumerates 2 checks on the population, only one of which has anything to do with food.
Earlier, Malthus writes:
“I think it will be allowed, that no state has hitherto existed (at least that we have any account of) where the manners were so pure and simple, and the means of subsistence so abundant, that no check whatever has existed to early marriages, among the lower classes, from a fear of not providing well for their families, or among the higher classes, from a fear of lowering their condition in life. Consequently in no state that we have yet known has the power of population been left to exert itself with perfect freedom.”
If you wish to not allow this, you need to prove both points: about means of subsistence being so abundant no fear exists, and about manners being pure and simple.
And more generally, you don’t grapple with the most fundamental point: population growth can be exponential, and resource growth is not.
So if there had been some span of time during which the human population was not limited in any way by a scarcity of available food and did not double at that rate, then that would be evidence that directly contradicts his theory.
The key point here is “not limited in any way by a scarcity of available food”.
The conversation went roughly like this
WrongBot: Malthus was wrong
MichaelVassar: what! why?
WrongBot: Well, here is evidence A (population growth data)
Emile: What? Evidence A is perfectly compatible with what Malthus said!
WrongBot: There is also evidence B (no signs of malnutrition in hunter-gatherers, etc.).
What I’m saying is that Evidence A alone is not enough to say Malthus was wrong. And that if you went back in time and showed evidence A only to Malthus, he would shrug. Do you disagree with this?
Evidence A without Evidence B is insufficient to wholly refute Malthus, yes, though I will point out that he predicts cycles of growth and starvation that are inconsistent with the slow and steady changes in population that seem to have characterized the spread of prehistoric humans. (There were massive die-offs at several points, but what evidence is available ties those points to natural disasters, not famine.)
I don’t want to say Malthus is wrong. His conclusions flow naturally from his assumptions.
Perhaps both sides of this spat could simply say Malthus is irrelevant when his assumptions (positive relationship between wealth and birth rates, population grows faster than economy) don’t hold?
simply say Malthus is irrelevant when his assumptions (positive relationship between wealth and birth rates, population grows faster than economy) don’t hold?
This is the correct view; his argument is practically deductive, and the only way around it is to take one of his escape holes: people collectively choosing a higher standard of living rather than offspring. The real questions we should be discussing are:
Applied to the argument in the post, the correct view is simply that Malthus was right. Applied to understanding of Malthus and Darwin in general I agree with your comment.
The demographic transition is temporary unless natural selection can’t influence desire for offspring. Hanson I think makes a similar argument as to why the future in his view is probably sort of Malthusian.
If I understand correctly, you’re saying that prehistorical hunter-gatherers avoided the Malthusian equilibrium by practicing a collective strategy of restraint from excessive breeding. But even if such a situation came to pass, it could never be a stable equilibrium over long periods of time. In such a situation, individuals who “cheated” by breeding above average and passing the same characteristic to their offspring would have caused their descendants to spread like wildfire, completely overwhelming those who restrained their breeding.
There is a general principle operating here akin to the old saying that nature abhors vacuum—namely, any population of reproducible organisms abhors a state where additional resources exist that could support further population growth all up to the Malthusian limit.
In such a situation, individuals who “cheated” by breeding above average and passing the same characteristic to their offspring would have caused their descendants to spread like wildfire, completely overwhelming those who restrained their breeding.
What simple adaptation do you propose to allow individuals to improve their average number of offspring, given that breastfeeding duration and menstruation-onset are traits of present-day foraging societies?
Or, for that matter, how do you explain the observed low population growth? Human fossils from that era don’t show signs of chronic malnutrition, and present-day foraging societies generally don’t have problems acquiring food.
There is a general principle operating here akin to the old saying that nature abhors vacuum—namely, any population of reproducible organisms abhors a state where additional resources exist that could support further population growth all up to the Malthusian limit.
This principle ignores the necessity of a mechanism for highly-variable population growth. Absent radical environmental changes (e.g. agriculture), such a mechanism has not been demonstrated.
What simple adaptation do you propose to allow individuals to improve their average number of offspring, given that breastfeeding duration and menstruation-onset are traits of present-day foraging societies?
Anything that makes people more phyloprogenitive will do the trick. In the long run, even behavioral mutations are conceivable, but cultural changes can also have a dramatic effect, and they act nearly instantaneously on evolutionary timescales. You yourself provide one possible answer: in the situation you describe, a mere cultural change that would shorten the breastfeeding period would, ceteris paribus, boost the fertility significantly.
Or, for that matter, how do you explain the observed low population growth? Human fossils from that era don’t show signs of chronic malnutrition, and present-day foraging societies generally don’t have problems acquiring food.
Obviously, the most reasonable explanation for low population growth is that the foragers were in a Malthusian equilibrium. The Malthusian principle says only that some resource constraint will stop further population growth, not what exactly that constraint will be. Other commenters in this thread have already suggested scenarios that wouldn’t necessarily leave too many emaciated corpses around.
The facts that early human populations: (1) expanded over vast continents, and (2) recovered from population bottleneck disasters imply that the potential for population growth was there, as far as the biological constraints on fertility are concerned. If local population growth wasn’t happening through prolonged periods of time, it means that something was preventing it. The idea that it was stopped by humans somehow successfully coordinating to limit their fertility and avoid the tragedy of the commons strikes me as implausible to the point of absurdity, for the reasons already mentioned. There is no plausible way how such a state of affairs could have emerged, and even if it did, it could never be stable through any significant period of time.
If local population growth wasn’t happening through prolonged periods of time, it means that something was preventing it. The idea that it was stopped by humans somehow successfully coordinating to limit their fertility and avoid the tragedy of the commons strikes me as implausible to the point of absurdity, for the reasons already mentioned.
I wholeheartedly agree.
Anything that makes people more phyloprogenitive will do the trick. In the long run, even behavioral mutations are conceivable, but cultural changes can also have a dramatic effect, and they act nearly instantaneously on evolutionary timescales. You yourself provide one possible answer: in the situation you describe, a mere cultural change that would shorten the breastfeeding period would, ceteris paribus, boost the fertility significantly.
Errr, yes, this happened. Approximately 10,000 years ago, in fact. Agriculture is a mere cultural change that shortened the breastfeeding period with a nearly instantaneous effect, by an evolutionary timescale.
The Malthusian principle says only that some resource constraint will stop further population growth, not what exactly that constraint will be.
Predation is not a resource constraint, yet it too halts population growth. The high rates of infant and maternal mortality that prevailed in all human societies prior to the past two centuries also limited population growth. Resource constraints, food or otherwise, are far from the sole determinant of population size.
I see no contradiction between those claims, and am surprised that you see one.
Malthus said that human population would catch up with available resources, and since the growth in resources was slower than the growth of population, and to estimate that, we can look at how fast population grows when there are very little constraints on resources, as in North America recently colonized by Europeans. When you look at population growth in the last two million years, you’re seeing population growth with resource constraints, and yes it’s much slower, which is what Malthus is saying. It certainly doesn’t prove him wrong.
Which resource constraints? Food? Prior to the appearance of agriculture, human fossils show almost no signs of malnutrition; afterwards, malnutrition is rampant.
Furthermore, you can’t look at 17th century Europeans and draw conclusions about hunter-gatherers. For example, hunter-gatherers typically breastfeed for 5-6 years, spacing out births far more than Europeans who had access to dairy animals. They also have less body-fat, pushing the onset of menstruation back to the late teens.
Like Malthus, you are looking at post-agricultural societies and assuming that pre-agricultural societies operate in precisely the same way. This is thoroughly and completely wrong.
(Again, I am drawing from Sex at Dawn’s 11th chapter.)
I bloody well am not.
I’m just saying that the numbers you show (population growth in 150 years of recently-colonized US; population growth in two million years of prehistoric humanity) do not show malthus wrong. Sure there are some things that Malthus didn’t know, and his model of reality was probably less accurate than ours. If you went back in time and showed him those numbers, and those numbers only, he would shrug and say “so what?”.
So this:
.… is unwarranted.
Is there some meaning of “wrong” which does not involve inaccurate models?
Malthus claimed that human population doubled every 25 years unless limited in some way by the amount of available food.
So if there had been some span of time during which the human population was not limited in any way by a scarcity of available food and did not double at that rate, then that would be evidence that directly contradicts his theory.
There is, in fact, such a span of time. As I have pointed out, for two million years of human existence, there is no substantial evidence of famine. And yet the population did not double at Malthus’s proposed rate. Or ten times his proposed rate. Or a hundred times his proposed rate. In what way is he not wrong?
That is a flawed argument, WrongBot. Visible signs of starvation aren’t necessary to assume humans were living along Malthusian limits. Rates of violence were extremely high amongst hunter gatherers (homicide was the most common cause of death). According to Stephen Pinker, 20-60% of males were murdered. This shouldn’t surprise those of us who understand human nature, people will gladly start killing each other before they let themselves starve to death.
In addition, females menstruating less is a natural response to malthusian conditions. The malthusian limits wouldn’t look like hungry bodies, it would look like fewer pregnant women per year, and more murders.
Ryan and Jetha have a lot to say about Steven Pinker, and none of it is kind. I suspect you will have your objections answered in my next post.
That probably tells me all I need to know about Ryan and Jetha. I’ll read them, but if they dislike Pinker’s conclusions rather than his writing style they probably don’t like rationality much as I understand the term, as he’s the only mainstream academic I’m aware of who visibly demonstrates the full suite of traditional rationalist virtues in essentially all of his writing. As you might guess, I’m a big fan of traditional rationalist virtues, but as you might not know unless you have seen me speak recently, I’m also a fan of those who energetically reject them, so this should be fun.
Their primary issue with him is not his writing style or his conclusions: it’s that he blatantly misrepresents anthropological data to support his bottom-line conclusions.
For example, the way he claims that “20-60% of males were murdered” in hunter-gatherer societies in order to support the superhappy conclusion that human societies are becoming less violent over time.
Wait, what exactly is wrong with this claim? If large percentages of the male population were murdered that are no longer being murdered, how is that not “less violent”?
If you’re going to address that point in your next post, then no rush.
I’ll be covering this in the next post, but the very short version is that it isn’t his reasoning, it’s that the 20-60% number is derived in an incredibly misleading way; there is substantial anthropological and fossil evidence that he is off by at least an order of magnitude.
Much less than 2% to 6% of modern people are murdered. If, as you claim, the numbers were an order of magnitude lower than Pinker’s claim, the number of homicide deaths would still be an order of magnitude higher than the current global average of about 8 per 100,000 per year.
ETA: Thats a good point FAWS, thanks. I changed it.
8 per 100,000 would be per year, not per lifetime. Assuming an average life span of 70 years that would be about 0.56%, just about one order of magnitude lower.
Me:
It was a one sentence comment. I’m starting to worry about this community’s ability to argue in good faith.
(This criticism is not necessarily directed at you, knb; it’s not a preposterously unlikely mistake, and I know I’ve made errors of this type. It’s their frequency on LessWrong that’s starting to get to me.)
I am having difficulty with this thread. As I understand biology:
all organisms (not just humans) tend to be able to produce more offspring then the environment can support
those individuals that produce the most living (and reproducing) offspring have their genes in higher frequency in the population
therefore natural selection works and populations evolve
Both Darwin and Wallace crystallized their ideas on evolve after reading Malthus. It doesn’t matter if Malthus was wrong on some minor points—his general idea is one of the foundations of evolution by natural selection. If you throw out Malthus’ general idea then you throw out natural selection. You cannot have it both ways.
Also, the idea that famine did not occur throughout human history is naive.
Are you reading Malthus, or just listening to the little caricature of Malthus in your head and the popular media? Your own link doesn’t even say that!
Basic grammar tells me that Malthus enumerates 2 checks on the population, only one of which has anything to do with food.
Earlier, Malthus writes:
If you wish to not allow this, you need to prove both points: about means of subsistence being so abundant no fear exists, and about manners being pure and simple.
And more generally, you don’t grapple with the most fundamental point: population growth can be exponential, and resource growth is not.
The key point here is “not limited in any way by a scarcity of available food”.
The conversation went roughly like this
WrongBot: Malthus was wrong
MichaelVassar: what! why?
WrongBot: Well, here is evidence A (population growth data)
Emile: What? Evidence A is perfectly compatible with what Malthus said!
WrongBot: There is also evidence B (no signs of malnutrition in hunter-gatherers, etc.).
What I’m saying is that Evidence A alone is not enough to say Malthus was wrong. And that if you went back in time and showed evidence A only to Malthus, he would shrug. Do you disagree with this?
Evidence A without Evidence B is insufficient to wholly refute Malthus, yes, though I will point out that he predicts cycles of growth and starvation that are inconsistent with the slow and steady changes in population that seem to have characterized the spread of prehistoric humans. (There were massive die-offs at several points, but what evidence is available ties those points to natural disasters, not famine.)
Why do you separate natural disasters from possible causes of famine?
Because Malthus’s theory doesn’t (so far as I’m aware) discuss discontinuous decreases in the available food supply.
But you are right that much of the devastation wrought by natural disasters is due to a shrunken food supply.
I don’t want to say Malthus is wrong. His conclusions flow naturally from his assumptions.
Perhaps both sides of this spat could simply say Malthus is irrelevant when his assumptions (positive relationship between wealth and birth rates, population grows faster than economy) don’t hold?
This is the correct view; his argument is practically deductive, and the only way around it is to take one of his escape holes: people collectively choosing a higher standard of living rather than offspring. The real questions we should be discussing are:
why does the demographic transition exist?
will it last indefinitely?
if it willn’t, when does it end? And will it reverse itself to high-fertility and either a population increase or a decrease in standard of living?
What repercussions does the end of the transition signal?
Question 4 leads us right into Robin Hanson’s crack of a future dawn and Dream Time scenario.
Applied to the argument in the post, the correct view is simply that Malthus was right.
Applied to understanding of Malthus and Darwin in general I agree with your comment.
The demographic transition is temporary unless natural selection can’t influence desire for offspring. Hanson I think makes a similar argument as to why the future in his view is probably sort of Malthusian.
If I understand correctly, you’re saying that prehistorical hunter-gatherers avoided the Malthusian equilibrium by practicing a collective strategy of restraint from excessive breeding. But even if such a situation came to pass, it could never be a stable equilibrium over long periods of time. In such a situation, individuals who “cheated” by breeding above average and passing the same characteristic to their offspring would have caused their descendants to spread like wildfire, completely overwhelming those who restrained their breeding.
There is a general principle operating here akin to the old saying that nature abhors vacuum—namely, any population of reproducible organisms abhors a state where additional resources exist that could support further population growth all up to the Malthusian limit.
What simple adaptation do you propose to allow individuals to improve their average number of offspring, given that breastfeeding duration and menstruation-onset are traits of present-day foraging societies?
Or, for that matter, how do you explain the observed low population growth? Human fossils from that era don’t show signs of chronic malnutrition, and present-day foraging societies generally don’t have problems acquiring food.
This principle ignores the necessity of a mechanism for highly-variable population growth. Absent radical environmental changes (e.g. agriculture), such a mechanism has not been demonstrated.
WrongBot:
Anything that makes people more phyloprogenitive will do the trick. In the long run, even behavioral mutations are conceivable, but cultural changes can also have a dramatic effect, and they act nearly instantaneously on evolutionary timescales. You yourself provide one possible answer: in the situation you describe, a mere cultural change that would shorten the breastfeeding period would, ceteris paribus, boost the fertility significantly.
Obviously, the most reasonable explanation for low population growth is that the foragers were in a Malthusian equilibrium. The Malthusian principle says only that some resource constraint will stop further population growth, not what exactly that constraint will be. Other commenters in this thread have already suggested scenarios that wouldn’t necessarily leave too many emaciated corpses around.
The facts that early human populations: (1) expanded over vast continents, and (2) recovered from population bottleneck disasters imply that the potential for population growth was there, as far as the biological constraints on fertility are concerned. If local population growth wasn’t happening through prolonged periods of time, it means that something was preventing it. The idea that it was stopped by humans somehow successfully coordinating to limit their fertility and avoid the tragedy of the commons strikes me as implausible to the point of absurdity, for the reasons already mentioned. There is no plausible way how such a state of affairs could have emerged, and even if it did, it could never be stable through any significant period of time.
I wholeheartedly agree.
Errr, yes, this happened. Approximately 10,000 years ago, in fact. Agriculture is a mere cultural change that shortened the breastfeeding period with a nearly instantaneous effect, by an evolutionary timescale.
Predation is not a resource constraint, yet it too halts population growth. The high rates of infant and maternal mortality that prevailed in all human societies prior to the past two centuries also limited population growth. Resource constraints, food or otherwise, are far from the sole determinant of population size.