Robin Hanson first proposed the idea of a “Great Filter” that has stopped any species from colonizing the galaxy. I’ve mostly heard it thought of as either something that prevents planets from reaching civilization levels close to ours (the leap to multicellular life is extremely improbable? too many planet-killer asteroids?), or disasters that destroy civilizations like ours before they’ve had a chance to expand past their home solar system (global nuclear war?).
I hadn’t really considered the idea that a civilization just can’t continue because life gets too easy.
Population Collapse has been getting some attention lately. I haven’t been too worried about it. My assumption was the fundamentalist religionists would continue having too many kids, we’d continue to draw them away by sheer force of being right, and the planet would chug along on its merry way.
I. Can You Make A Pencil?
In one of the best SF books ever, Peter Watts’s character claims that Technology Implies Belligerence
the real issue was what tools are for. To the Historians, tools existed for only one reason: to force the universe into unnatural shapes. They treated nature as an enemy, they were by definition a rebellion against the way things were.
Technology is a stunted thing in benign environments, it never thrived in any culture gripped by belief in natural harmony. Why invent fusion reactors if your climate is comfortable, if your food is abundant? Why build fortresses if you have no enemies? Why force change upon a world that poses no threat?
The broader point is that a super-advanced race faced selection pressure from constant conflict with other intelligences, and thus high-tech implies belligerence. We don’t have such an enemy, thank goodness. But the premise itself is suspect. We have continued to develop technology for many decades despite a lack of external threat. People aren’t going to just stop making things, they’ll just make them slower. Maybe bad on the individual scale, but immaterial on geologic timelines. The galaxy should still be ours soon enough. Right?
Well, can you make a pencil? The classic essay “I, Pencil” points out that no single human on earth has the ability to make a standard pencil. The resources, skills, and knowledge needed to produce this particular artifact are spread across thousands of individuals (at a minimum) across a great distance working together. A single person could, with enough time, create a crude reproduction of a single pencil that would basically get the job done. But it would take astronomically more time and effort, and not be nearly as good.
And that’s just a pencil.
Back in 2010 Charles Stross made a very rough estimate that simply keeping the world from regressing technologically (preventing a new “dark age”) would require between 0.1B-1.0B people. Tyler Cowen conjectured that a population reduced to 1B would be at least 15% poorer, and in fact significantly more people would be needed to keep the world at its present state due to distribution of wealth/productivity/fixed costs.
That was back in 2010. I suspect it’s far more today. Our global economy is so interconnected and competitive that even relatively moderate disturbances to the supply chain can have ripple effects that magnify effects tremendously.
We are dependent on a large population to support incredibly niche specializations of labor/knowledge that allow us to reap huge societal rewards. Appreciable decrease in population could mean we are literally unable to retain our current tech level.
II. The Religious Are Running Out Of Fucks
My idea had been that others can reproduce physical human units, and we can reproduce the effective memes that motivate those humans, thus preserving both culture and population levels, and thus our way of life.
Earlier this year Isabel of the Effective Altruism forums posted Retrospective on Shall the Religious Inherit The Earth. It’s good, and worth a read, and it’s also very long.
Short version: I was wrong. Not even the religious fundamentalists are having kids at replacement rates. As soon as people get rich enough to live at modern standards, they fail to reproduce.
That’s right, not even the Mormons. Not even the Muslims. Not even the Evangelical Quiverful movement. All of them have kids that mostly say “I’d rather be comfortable, I ain’t keeping up this silly tradition” and in aggregate fall below 2.1 children per couple, once they have enough GDP/education/etc.
In retrospect, this makes sense. Kids are apparently the most fulfilling and meaningful thing humans can do in their lives (thanks Azathoth?)… but they’re a huge pain in the ass. I got myself sterilized after having zero kids, cuz F that. Even the people I know who plan to have children (less than half of my social group!) almost exclusively are having only 1 childrens. Why wouldn't any sufficiently advanced society make themselves as comfortable as they can? I assume the returns on Meaningfulness diminish per child, and the majority comes in that first kid. Some couples may chase the dragon, but if you can maximize the Comfort/Meaning score at one kid… why not?
The only maybe-possibly exceptions are ultra-orthodox jews and amish, neither of which will be going to the stars or solving aging.
III. The Tech Predator-Prey Cycle
I don’t expect the human race to literally evolve to extinction. I expect that (if nothing changes) we will reach Peak Humans this century, and begin to decline in population. Eventually we’ll get to a point where we can’t maintain our current tech level, productivity drops, and Quality-of-Life drops as well.
Once we’ve regressed to a certain point, humans will begin to have children again. When wealth/QoL/education/comfort/whatever reverts to pre-Population Decline levels, the joy of children will be competitive again. Not because children rise in desirability, but because the rival goods of Vidja and pr0n won’t be very good anymore. (Plus whatever chicks are into that’s better than kids. A career, I guess? Good romance fanfic and tumblr?)
It will take a number of decades for this to reverse the Decline Of Man, but we’ll get there eventually. Slowly quality of life will increase as population rises and tech level rises. Kids won’t be as fun, fertility will start to drop again, and a few generations after that we’ll get population shrinkage again. The whole cycle begins anew.
It’s basically the predator-prey cycle, but with Tech Levels and Fertility Rates.
IV. Stable Great Filter
This dynamic would prevent a species from ever getting off its homeworld. It would work even if every single step from “the star forms” to “2022 human tech level” is extremely common. It would work to entrap even species with great resources and intelligence and peacefulness. A society can completely solve most of its people’s problems and eliminate war, and still end up here. All it takes is for “having less than 2.1 children per couple” to have better expected utility for most couples in the population, compared to having more.
The universe could be teeming with life right now. There could be hundreds of millions of planets out there, either in the process of bootstrapping back to Golden Ages, or currently producing uncountable terrabytes of beautiful art of all kinds. And we’ll never meet any of them.
V. Agent Smith Did Nothing Wrong
If there is a bright side to this, it’s that the 90s aren’t lost to us forever. Agent Smith told us, in 1999, that we were living at the peak of human civilization. We didn’t know at the time how correct he was, but we see it now. Perhaps that Golden Age is in our past. We can take comfort in the thought that many of us got to experience it, and that our descendants will get to experience it again and again, many many many times, before our sun dies.
New Great Filter Just Dropped
If society at large were more supportive of parents, families and children, I'd probably have some. But for all their talk, politicians don't seem interested in moving society in that direction. There seems to be a lack of political will to keep humanity growing. I'm not personally invested in the survival of humanity, so instead of going through the enormous hassles of having children, I'm also comfortable with living long and dying out.
Hmm, I don't believe this trap is stable over the long term, though it might work through a few cycles.
It's true that in the short and maybe medium term cultural evolution effects like this would dominate.
Over the long term though regular evolution would intervene. It seems like in our past it was sufficient for evolution to encode
1) Desire for sex / sex being fun
2) Loving your children and fighting for their survival once they exist
Everything else took care of itself.
Now that we're intervening in that cycle we should expect new adaptions to develop. In the near future that might only manifest in things like more widespread allergic reactions to birth control or it being less effective than expected. That's probably not sufficient though as we could easily adjust the birth control faster than evolution can get around it.
In the far future I see different possibilities:
- strong inborn desires for having many children/descendants
- what we would now consider pregnancy fetishes - non procreative sex just not feeling that good in comparison
- pregnancy itself becoming easier and more pleasant
- the way children develop/grow up becoming less burdensome for parents
- basically any other change that leads to people having more children
(This all obviously assumes that we won't have massive technological advances that make all of this not matter.)