“Nevertheless, I believe we can make some relatively safe logical deductions. Everybody seems to agree that merfolk have two mammary glands, which means the females bear one, or occasionally two, offspring at a time. Given their anatomical base of arms and hands, they likely carry their young as well, as do all land-dwelling primates. Yet due to their relatively small size in comparison to sharks and squid and other threats, merfolk, especially the young, would be vulnerable to predation. Thus it is my opinion that they are social mammals that live together in large numbers for protection. It is improbable they would have a complex language to communicate with one another as do humans, as we only began talking in a unique and complex form some 100,000 years ago. But I would argue they have a rudimentary one. Great apes, for example, can comprehend symbols; they understand that this stands for that even though this has no resemblance to that. They can learn American Sign Language, computer language, and spoken language. They only have trouble with syntax and stringing symbols together into meaningful sentences. So, yes, merfolk likely possess a language, but one at the linguistic stage of early hominins rather than the articulatory capabilities of modern humans. Does this mean they would possess theory of mind? That is, the ability to attribute thoughts, desires, and intentions to others; to predict or explain their actions; and to posit their intentions? Human children develop theory of mind at three or four years of age. Prior to that time, they do not realize that they or others may have incomplete information. Whether merfolk have this ability or not is anyone’s guess.

“In considering the technological achievements of merfolk, I believe they would be rather unremarkable. Assuming merfolk have a brain size on par with Australopithecus, and a similar level of manual dexterity, they would have the cognitive complexity and physical ability to use simple tools for acquiring and processing animal and plant food. Cracking mollusks, butchering carcasses, disarticulation, marrow extraction, cutting stalks. Nevertheless, the marine realm offers no fibers suitable for basketry or weaving clothing, and the lack of fire would make pottery and metallurgy impossible. These two facts alone would hamper any sort of cultural and technological innovation, preventing merfolk from evolving contemporaneously with the genus Homo beyond an early Paleolithic lifestyle. Sorry, folks, there’s no shining Atlantis down on the seabed somewhere.