The Murderous Tribe
Imagine two tribes of hunter-gatherers, 50 people each. Tribe One believes that killing is always wrong, while Tribe Two thinks killing is okay–so long as it’s a member of another tribe. During a harsh winter with low food levels, the two tribes venture outside their usual zones and run into each other. Tribe Two kills half of Tribe One and takes some of their food.
Now Tribe One has only 25 people, while Tribe Two still has 50. So the percentage of total population that believes killing is justified went from 50% to 67% (50 out of 75 is 67%).
Okay, well maybe that’s kind of misleading. The belief increasing from 50% to 67% wasn’t the result of 17% of people being convinced it was right. It is because the people who didn’t believe it were selected out of the population. Assuming all else equal, both tribes will eventually increase in population until the total population reaches 100 once again, the end effect will be as if 17 people converted.
What is going on is that being willing to kill members of other tribes is an evolutionarily beneficial idea.
In our example, we didn’t need to start with two tribes. There could have been 1000 tribes–50% pacifist, 50% violent. What happens when they repeatedly interact with each other in the long run? Most of the population become violent.
Biological organisms aren’t the only things that evolve via natural selection. Ideas do too.
Propagation of Ideas by Natural Selection
We’d like to think our beliefs are correct. Near 100% of people used to believe the Sun went around the Earth. Now we mostly think the opposite. “Earth orbits the Sun” is a factually correct idea that seemed to spread due to the merit of its accuracy.
Being correct is one way that an idea could gain traction. Having traits to help become naturally selected is another. “We should care about our own tribe more than others” seems like not a factually correct belief, or at least not an obviously correct one. It is popular because it was an evolutionarily advantageous belief–when there were collisions between believers and nonbelievers, those who did believe it were more inherently more likely to gain from collision.
Evolutionarily Advantaged Ideas
Here are four ways to increase the % of population that has a particular belief X:
- Decrease the population of people who don’t believe X
- Increase the population of people who believe X
- Convince people who don’t believe X to believe X
- Deter new people from believing alternatives to X
Ideas that inherently do one or more of these will be favored in selection. An idea is inherently advantaged if acting out on that idea causes the % of people with that idea to increase. Heliocentrism does not inherently spread, whereas tribalism does–via killing off those who are not tribal. More examples:
- Any belief that creates advantages in war
- An emphasis on science & technology. Between two countries all-else-equal, the technology-loving country has an advantage.
- Nationalism and strong national identities. This should work in similar ways to tribalism.
- Policies like having a standing army or draft.
- Racism in the old-fashioned way–straight-up “people of X color are subhuman/shouldn’t exist”. This is essentially the same example as tribalism.
- Family centrism. This is more of a biological trait than a psychological one, but I’ll mention it here. Suppose 50% of people would sacrifice the lives of two strangers to save their child, and the other 50% would sacrifice their child to save the lives of two strangers. Assuming there is some genetic component to this belief, you’d expect the population to converge to 100% of the population being willing to sacrifice two strangers to save their own child, because that gene would be selected.
- Growth-oriented ideas
- “Have lots of children” is an obvious one. If 50% of the population believed everyone should have lots of children, and 50% believed no one should have children, what % of the population will have each belief in 100 years?
- Mainstream economics. Given that you’re reading this, you are likely living in an above-average wealthy country, and wealth countries tend to have strong growth policies.
- Countries which prioritize growth over sustainability gain a military advantage, in addition to directly increasing the % of population that supports growth.
- “My country shouldn’t worry about climate change”–A country that worries a lot about climate change needs to sacrifice growth, thus putting it at a disadvantage compared to other countries, and after some time it could lose % population of the world, and also it might have economic troubles that cause ideas from rich countries which don’t care about climate change to seep in.
- Anti-euthanasia. We take this for granted, but “You should live your life, even if you are suffering” is an evolutionarily advantaged belief. Let’s say there is a disease so permanently crippling and painful that 90% who get it really, really beg to be euthanized (and somehow succeed in convincing their doctors), while the other 10% still experience pain but really, really believe in suffering through the pain. Now if you conduct a poll on “Is this disease so bad you’d want to die? Let’s ask some patients and find out”, you’d find that a large percentage wants to carry out living.
- (Abrahamic) Religion
- The punishment for apostasy can range from social stigma to death, deterring people from believing competing ideas. There is also the threat of eternal suffering for nonbelief.
- The first three commandments are about deterring people from thinking about competing ideas.
- Religions tend to have some form of evangelism.
- “Be fruitful and multiply” is growth-oriented.
- Simple, easy-to-explain ideas. It is easy to spread simple ideas, difficult to spread complex ones.
- Ideas that human brains are particularly good at remembering. E.g., a catchy slogan or song.
In general, I think we should be marginally more skeptical of all of these ideas. They are popular ideas, not necessarily because they are right, but because they have beneficial selection traits. The idea could still be right
Evolutionarily Disadvantaged Ideas
The converse is that we should be more accepting of evolutionarily disadvantaged ideas, or evolutionary dead-ends. A very basic list is just the opposite of the previous:
- Ideas that don’t lead to strong militaries, e.g. not focusing so much on science and technology
- Treating all humans equally. This sounds obvious and easy, but it is really not! Who would value a stranger’s child as equal to their own child?
- Sustainability-oriented ideas, or even population/economic-shrinking ideas, as opposed to permanent growth.
- Antinatalism. Already, more people especially in the west are choosing to be childfree.
- Environmentalism. Note the most radical forms like the Voluntary Human Extinction Movement.
- More strongly, suicide. Suicide is the most extreme evolutionary dead-end. Yet a lot of people commit suicide every year. Maybe the idea that life sucks/isn’t worth living is more valid than people give it credit for, and a lot of people needlessly suffer their entire lives. It is hard to have a good two-sided discussion between two opposing sides because the people most agreeing with the idea of suicide are dead. Of course, raising the status of this is a social danger because it would cause more people to die of suicide.
- Anti-religion. Note this mostly applies to the Abrahamic religions. Buddhism is kind of a weird one because it is somewhat antinatalist, so we would have expected it to be selected out of the population.
- Complex, hard-to-understand, hard-to-remember ideas.
To correct for selection, we should marginally lower the acceptance of advantaged ideas and raise the acceptance of disadvantaged ideas. And when considering which ideas are the most popular, we need to make sure we’re not falling to selection effects.
A future post will contain a counterargument to all this–why we shouldn’t care about idea selection and just use whatever ideas are easy to propagate.