The Drake Equation: Communication

Turning to fc, the fraction of biotas with intelligent species where at least one species becomes capable of interstellar communication.

Some such species may be incapable of that, like cetaceans, because they are aquatic. Cetaceans also don’t have tentacles or pincers. So we must turn to the history of our species for clues.

The first step along the way is agriculture, since it enables larger population densities and larger-scale societies than foraging can. What is curious about humanity and agriculture is that present-day humanity did not have it for most of its some 40,000 – 100,000 years of its existence. But in the Holocene, after the end of the last ice age, humanity invented agriculture independently in several places in the world. I have seen a speculation that this curious timing is due to the climate being more stable in the Holocene than in the time since the previous interglacial about 100,000 years ago. An unstable climate makes it difficult to get started with agriculture, since the weather can turn bad for it too quickly.

In this connection, Jared Diamond has made a strong case that Eurasian people got ahead of the rest of humanity because they could exchange crop plants across the length of their continent. Also because it had some conveniently domesticatable animals. By comparison, it was difficult to get potatoes and llamas from the Andes to the North American Rockies, where they can thrive, because of the tropical-climate places in between.

Next is persistent information storage: writing. It can easily outlive its writers, and it does not need the memory cues that are convenient for memorizing large amounts of memory. Rhythmic poetry was a much-valued art, and its rhythms helped to jog the memories of its memorizers. In fact, some people apparently considered writing a bad thing because it would make people’s memories atrophy and make people only appear to be learned (The Internet Classics Archive | Phaedrus by Plato).

Writing was only invented in two or three places: Sumeria, Central America, and maybe also China. But once it was invented, it was widely copied, and many people invented writing systems out of awareness that it was possible: stimulus diffusion.

After that was development of science, but that was difficult and slow. It started in classical Greece and continued into the early Roman Empire, where it was interrupted by the “Crisis of the Third Century”: strife and civil war. It did not restart until over a millennium later in western and central Europe, and even then, it was slow going at first.

There is a further problem. The social-brain theory of intelligence suggests that sentient species may prefer to be considered with social relations and gossip and the like; that sometimes seems rather evident in our species. That extends to anthropomorphizing nonhuman species like pet species, like making LOLcat pictures.

However, some of us have Asperger’s syndrome, which may help its sufferers understand impersonal things and features and relations. Not many, but enough to be useful for the rest of us. So might other sentient species have Asperger-like variants?

Considering all these factors, fc may be much less than 1.