Gamma Andromeda, where philosophical stoicism went too far. Its inhabitants, tired of the roller coaster ride of daily existence, decided to learn equanimity in the face of gain or misfortune, neither dreading disaster nor taking joy in success.

But that turned out to be really hard, so instead they just hacked it. Whenever something good happens, the Gammandromedans give themselves an electric shock proportional in strength to its goodness. Whenever something bad happens, the Gammandromedans take an opiate-like drug that directly stimulates the pleasure centers of their brain, in a dose proportional in strength to its badness.

As a result, every day on Gamma Andromeda is equally good compared to every other day, and its inhabitants need not be jostled about by fear or hope for the future.

This does sort of screw up their incentives to make good things happen, but luckily they’re all virtue ethicists.

Zyzzx Prime, inhabited by an alien race descended from a barnacle-like creature. Barnacles are famous for their two stage life-cycle: in the first, they are mobile and curious creatures, cleverly picking out the best spot to make their home. In the second, they root themselves to the spot and, having no further use for their brain, eat it.

This particular alien race has evolved far beyond that point and does not literally eat its brain. However, once an alien reaches sufficiently high social status, it releases a series of hormones that tell its brain, essentially, that it is now in a safe place and doesn’t have to waste so much energy on thought and creativity to get ahead. As a result, its mental acuity drops two or three standard deviations.

The Zyzzxians’ society is marked by a series of experiments with government – monarchy, democracy, dictatorship – only to discover that, whether chosen by succession, election, or ruthless conquest, its once brilliant leaders lose their genius immediately upon accession and do a terrible job. Their government is thus marked by a series of perpetual pointless revolutions.

At one point, a scientific effort was launched to discover the hormones responsible and whether it was possible to block them. Unfortunately, any scientist who showed promise soon lost their genius, and those promoted to be heads of research institutes became stumbling blocks who mismanaged funds and held back their less prestigious co-workers. Suggestions that the institutes eliminate tenure were vetoed by top officials, who said that “such a drastic step seems unnecessary”.

K’th’ranga V, which has been a global theocracy for thousands of years, ever since its dominant race invented agricultural civilization. This worked out pretty well for a while, until it reached an age of industrialization, globalization, and scientific discovery. Scientists began to uncover truths that contradicted the Sacred Scriptures, and the hectic pace of modern life made the shepherds-and-desert-traders setting of the holy stories look vaguely silly. Worse, the cold logic of capitalism and utilitarianism began to invade the Scriptures’ innocent Stone Age morality.

The priest-kings tried to turn back the tide of progress, but soon realized this was a losing game. Worse, in order to determine what to suppress, they themselves had to learn the dangerous information, and their mental purity was even more valuable than that of the populace at large.

So the priest-kings moved en masse to a big island, where they began living an old-timey Bronze Age lifestyle. And the world they ruled sent emissaries to the island, who interfaced with the priest-kings, and sought their guidance, and the priest-kings ruled a world they didn’t understand as best they could.

But it soon became clear that the system could not sustain itself indefinitely. For one thing, the priest-kings worried that discussion with the emissaries – who inevitably wanted to talk about strange things like budgets and interest rates and nuclear armaments – was contaminating their memetic purity. For another thing, they honestly couldn’t understand what the emissaries were talking about half the time.

Luckily, there was a whole chain of islands making an archipelago. So the priest-kings set up ten transitional societies – themselves in the Bronze Age, another in the Iron Age, another in the Classical Age, and so on to the mainland, who by this point were starting to experiment with nanotech. Mainland society brought its decisions to the first island, who translated it into their own slightly-less-advanced understanding, who brought it to the second island, and so on to the priest-kings, by which point a discussion about global warming might sound like whether we should propitiate the Coal Spirit. The priest-kings would send their decisions to the second-to-last island, and so on back to the mainland.

Eventually the Kth’ built an AI which achieved superintelligence and set out to conquer the universe. But it was a well-programmed superintelligence coded with Kth’ values. Whenever it wanted a high-level decision made, it would talk to a slightly less powerful superintelligence, who would talk to a slightly less powerful superintelligence, who would talk to the mainlanders, who would talk to the first island…

Chan X-3, notable for a native species that evolved as fitness-maximizers, not adaptation-executors. Their explicit goal is to maximize the number of copies of their genes. But whatever genetic program they are executing doesn’t care whether the genes are within a living being capable of expressing them or not. The planet is covered with giant vats full of frozen DNA. There was originally some worry that the species would go extinct, since having children would consume resources that could be used hiring geneticists to make millions of copies of your DNA and stores them in freezers. Luckily, it was realized that children not only provide a useful way to continue the work of copying and storing (half of) your DNA long into the future, but will also work to guard your already-stored DNA against being destroyed. The species has thus continued undiminished, somehow, and their fondest hope is to colonize space and reach the frozen Kuiper Belt objects where their DNA will naturally stay undegraded for all time.

New Capricorn, which contains a previously undiscovered human colony that has achieved a research breakthrough beyond their wildest hopes. A multi-century effort paid off in a fully general cure for death. However, the drug fails to stop aging. Although the Capricornis no longer need fear the grave, after age 100 or so even the hardiest of them get Alzheimers’ or other similar conditions. A hundred years after the breakthrough, more than half of the population is elderly and demented. Two hundred years after, more than 80% are. Capricorni nursing homes quickly became overcrowded and unpleasant, to the dismay of citizens expecting to spend eternity there.

So another research program was started, and the result were fully immersive, fully life-supporting virtual reality capsules. Stacked in huge warehouses by the millions, the elderly sit in their virtual worlds, vague sunny fields and old gabled houses where it is always the Good Old Days and their grandchildren are always visiting.