Is ape sign language completely dead?

[Measure_for_Measure]

@echoreply

Also, some of it is just how science works. Initial findings are later found to be wrong. That is to be expected with the scientific method, and is everything working exactly as designed. If we already knew the answer, then why would anyone have bothered with the experiment in the first place?

This. National Geographic was describing the work of credentialed scientists. This century it was discovered that psychology had a replication problem, but I don’t expect Nat Geo to be more clairvoyant than most psychologists in the field.

Note that there was vigorous debate about Koko et al in the late 1970s: it was dubbed “The Ape Wars” in the popular scientific press. My understanding was that at best Koko et al were nowhere near the level of a human 2 year old. I don’t find either position to be implausible a priori, though the Koko study lacked rigor and the conclusions as reported in the popular press were in error. (ETA: Erm, I see from wiki that some were claiming that Koko had an IQ of 70 or 90. I don’t recall claims that expansive.)

Semi relevant: today’s New York Times has an article about cross-specie communication between a caterpillar/butterfly and certain ant colonies: the former tricks the latter. Gifted.
“Trilobites: The Password That Lets Caterpillars Hide in an Ant’s Lair: Some butterfly species can’t grow unless they trick ants into taking them home with a complex rhythmic signal.”

https://www.nytimes.com/2026/02/25/science/caterpillar-ant-language.html?unlocked_article_code=1.PFA.NSqN.2oxVuauaYjU1&smid=url-share

@echoreply

Other topic: have cetaceans been mentioned? Due to the rule of cute/magnificent animals pushing marginal results into the popular press, I’ve seen several stories about whale and dolphin songs possibly being language, rather than simple signaling.

See my multi-decade thread here and note the shifts in conventional wisdom:

Language: If whales had it, would we know?

If whales sang love sonnets or expositions on philosophy and mathematics to one another, would we know about it? I suppose that this is a signal processing problem: given what we know about whales’ listening and vocalization abilities, is there an upper bound to the complexity of what they could be saying to one another? Ditto for elephants.