Follow-up to: Boring Advice Repository
Many practical problems in instrumental rationality appear to be wide open. Two I've been annoyed by recently are "what should I eat?" and "how should I exercise?" However, some appear to be more or less solved. For example, various mnemonic techniques like memory palaces, along with spaced repetition, seem to more or less solve the problem of memorization.
I would like people to use this thread to post other examples of solved problems in instrumental rationality. I'm pretty sure you all collectively know good examples; there's a comment I can't find from a user who said something like "taking a flattering photograph of yourself is a solved problem," and it's likely that there are other useful examples like this that aren't common knowledge. Err on the side of posting solutions which may not be universal but are still likely to be helpful to many people.
(This thread is allowed to not be boring! Go wild!)
If we didn't have brainware for favoring status, people wouldn't have a preference for attaining it, or the ability to recognize it, at all. I suspect anyone who's been through an ordinary public school will be able to attest that humans, from an early age, tend to have some degree of motivation to have standing among their peers, and are able to follow cues to determine who has such standing and who does not. If we've established that such apparatus exists at all, it's not a big jump to implementing it in mate selection.
I'm going to disagree with Kindly and say that there is a readily apparent advantage here. For most of our evolutionary history, high status would be associated with ability to provide for offspring. A leader who has many underlings paying tribute can much more easily support raising children in safety and abundance than one of the underlings whose resources are being taken in tribute. If we're looking at a culture with really large status differentials, say, Ancient Egypt, a Pharaoh who's already had two hundred kids by various women is still more able to support the raising of a few more than a peasant laborer who hasn't had any children at all yet.
We can confirm via genetics that humans alive today have considerably fewer male ancestors than female, because it was rarer for women to go without having any children than men, but men were more likely to have many children by different partners. Reports of sexual activity among men and women support the same pattern today.
If both men and women had drives that amounted only to "get laid, don't get killed," we would be unlikely to observe such a pattern. Among animals, organisms with more than a very small amount of processing power tend to implement more complex selection strategies than this. Take, for example, all the herbivores where the males have horns they use to compete with other males over females.
Keep in mind that beyond attempting to survive and have offspring, there's a genetic advantage in displacing competitors. Every specimen benefits from getting their genes as large a share of the next generation as possible. This will tend to complicate reproductive strategies well beyond the level of "survive and have kids."