From Michael Erard at Science:
About 100,000 years ago, ancient humans started etching lines and hashtag patterns onto red rocks in a South African cave. Such handiwork has been cited as the first sign our species could make symbols—distinct marks that stand for some meaning—and thus evidence of a sophisticated mind. But a new study, reported here this week at Evolang, a biannual conference on the evolution of language, finds that these markings and others like them lack key characteristics of symbols. Instead, they may have been more for decoration or enjoyment.
…
Tylén’s team found that, in the eyes of today’s humans, younger markings had more clearly defined visual elements and were more aesthetically regular than older ones. Participants also could remember and reproduce the more recent markings better than the older ones. But people weren’t able to sort the markings into the correct groupings by place, and weren’t able to distinguish signs from each other.
That’s a minimal test of being a symbol—being distinct from another marking—and the engravings failed. “That suggests that we’re not looking at a symbolic system in the sense that each marking has an individual meaning,” Tylén said to meeting attendees. More.
Some colleagues, while polite, were not convinced and I am not either. The markings were not intended to communicate with the Danish university students enrolled in Tylén’s study and may reference matters unknown to them.
More generally, all art is symbolic in some sense. Even what seems merely decorative (flowery wallpaper and sofa fabric come to mind) is both a status marker and an expression of a view of the world. The blank spaces and stick furniture of minimalism convey a message too, by what is missing. One wonders why that seems hard to understand.
Life forms that cannot think symbolically would not do any kind of art at all.
See also: Neanderthal artwork found: “Academic bombshell” obliterates “lesser human” theory?
and
Early human religion: A 747 built in the basement with an X-Acto knife