Communicating With Other Apes?

I have always suspected that humans have rather good abilities to deduce the emotions of great apes. This seems confirmed in a recent study (https://www.theguardian.com/science/2023/jan/24/humans-able-to-understand-other-apes-better-than-thought-research-suggests). I remember, decades ago, setting an undergraduate project at Swansea University. It used photographs of behaviours in Chimpanzees, Gorillas etc, taken from research papers. Untrained undergraduates were asked to predict the emotions being expressed in the photographs by the apes. It was found that untrained undergraduates were surprisingly good at this. Even more strangely, a group of educationally-challenged young people were superior to the undergraduate group. It was tentatively concluded (the study was never published), that the folk with the learning difficulties were better, as they relied more on body language rather than verbal communication. Intriguing. It certainly seems worth repeating, using the improved technologies described in this recent study!